TPress
2023
Trinler, U.; Heitzmann, D. W. W.; Hitzeroth, S.; Alimusaj, M.; Rehg, M.; Hogan, A.
In: Prosthet. Orthot. Int., Bd. 47, Nr. 1, S. 94–100, 2023, ISSN: 0309-3646.
@article{Trinler2023,
title = {Biomechanical comparison of a 3D-printed prosthetic foot with conventional feet in people with transtibial amputation: A prospective cohort study},
author = {U. Trinler and D. W. W. Heitzmann and S. Hitzeroth and M. Alimusaj and M. Rehg and A. Hogan},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2022874959&from=export},
doi = {10.1097/PXR.0000000000000180},
issn = {0309-3646},
year = {2023},
date = {2023-08-01},
journal = {Prosthet. Orthot. Int.},
volume = {47},
number = {1},
pages = {94–100},
publisher = {Ovid Technologies (Wolters Kluwer Health)},
address = {U. Trinler, BG Klinik Ludwigshafen, Ludwig-Guttmann-Str. 13, Ludwigshafen, Germany},
abstract = {Introduction: The method of 3D printing is increasingly gaining utilization in clinical applications and may support prosthetic fitting. The aim was to compare biomechanical outcomes of people with a transtibial amputation using a novel, individualizable, 3D-printed prosthetic foot (ComfyStep, Mecuris) with two conventional, widely used prosthetic feet during level ground walking using a 3D motion analysis system. Methods: Ten individuals with an unilateral transtibial amputation were fitted with 3 prosthetic feet (ComfyStep, Assure/Össur, DynamicMotion/Ottobock) using their current, well-fitting socket. They had at least 1 week of familiarization for each foot before gait analyses were conducted. Kinematics and kinetics as well as roll over shape (ROS) length and radius were calculated and compared between feet. Results: The sound side gait parameters of the participants were comparable when using different feet. However, there were differences on the affected side. The statistical analysis revealed that the 3D-printed foot differed significantly compared with the conventional feet in the following aspects: reduced range of motion, increased plantar flexion moment, reduced plantar flexion power, larger ROS radius, less favorable energy ratio, and higher overall stiffness. Conclusion: In principle, 3D-printed feet have advantages over conventional “off the shelf” feet, as their biomechanical characteristics could be adjusted more in detail according to the patient needs. Although, differences between conventional feet and the ComfyStep were shown. Whether these differences have a negative clinically relevant effect remains unclear. However, results suggest that commercially available 3D-printed feet should incorporate systematically better adjustments, for example, for stiffness, to enhance prosthetic performance.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Introduction: The method of 3D printing is increasingly gaining utilization in clinical applications and may support prosthetic fitting. The aim was to compare biomechanical outcomes of people with a transtibial amputation using a novel, individualizable, 3D-printed prosthetic foot (ComfyStep, Mecuris) with two conventional, widely used prosthetic feet during level ground walking using a 3D motion analysis system. Methods: Ten individuals with an unilateral transtibial amputation were fitted with 3 prosthetic feet (ComfyStep, Assure/Össur, DynamicMotion/Ottobock) using their current, well-fitting socket. They had at least 1 week of familiarization for each foot before gait analyses were conducted. Kinematics and kinetics as well as roll over shape (ROS) length and radius were calculated and compared between feet. Results: The sound side gait parameters of the participants were comparable when using different feet. However, there were differences on the affected side. The statistical analysis revealed that the 3D-printed foot differed significantly compared with the conventional feet in the following aspects: reduced range of motion, increased plantar flexion moment, reduced plantar flexion power, larger ROS radius, less favorable energy ratio, and higher overall stiffness. Conclusion: In principle, 3D-printed feet have advantages over conventional “off the shelf” feet, as their biomechanical characteristics could be adjusted more in detail according to the patient needs. Although, differences between conventional feet and the ComfyStep were shown. Whether these differences have a negative clinically relevant effect remains unclear. However, results suggest that commercially available 3D-printed feet should incorporate systematically better adjustments, for example, for stiffness, to enhance prosthetic performance.
Manz, Sabina; Seifert, Dirk; Altenburg, Bjoern; Schmalz, Thomas; Dosen, Strahinja; Gonzalez-Vargas, Jose
In: Clinical Biomechanics, Bd. 106, S. 105988, 2023, ISSN: 0268-0033.
@article{Manz2023,
title = {Using embedded prosthesis sensors for clinical gait analyses in people with lower limb amputation: A feasibility study},
author = {Sabina Manz and Dirk Seifert and Bjoern Altenburg and Thomas Schmalz and Strahinja Dosen and Jose Gonzalez-Vargas},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2024655048&from=export},
doi = {10.1016/j.clinbiomech.2023.105988},
issn = {0268-0033},
year = {2023},
date = {2023-06-01},
journal = {Clinical Biomechanics},
volume = {106},
pages = {105988},
publisher = {Elsevier BV},
address = {J. Gonzalez-Vargas, Ottobock SE & Co. KGaA, Duderstadt, Germany},
abstract = {Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.
Darter, B. J.; Syrett, E. D.; Foreman, K. B.; Kubiak, E.; Sinclair, S.
In: PLoS ONE, Bd. 18, Nr. 2 February, 2023, ISSN: 1932-6203.
@article{Darter2023,
title = {Changes in frontal plane kinematics over 12-months in individuals with the Percutaneous Osseointegrated Prosthesis (POP)},
author = {B. J. Darter and E. D. Syrett and K. B. Foreman and E. Kubiak and S. Sinclair},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2023020092&from=export},
doi = {10.1371/journal.pone.0281339},
issn = {1932-6203},
year = {2023},
date = {2023-01-01},
journal = {PLoS ONE},
volume = {18},
number = {2 February},
address = {B.J. Darter, Department of Physical Therapy, Virginia Commonwealth University, Richmond, VA, United States},
abstract = {Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.
2022
Ernst, M.; Altenburg, B.; Schmalz, T.; Kannenberg, A.; Bellmann, M.
Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes Artikel
In: J. NeuroEng. Rehabil., Bd. 19, Nr. 1, 2022, ISSN: 1743-0003.
@article{Ernst2022,
title = {Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes},
author = {M. Ernst and B. Altenburg and T. Schmalz and A. Kannenberg and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2014862458&from=export},
doi = {10.1186/s12984-022-00983-y},
issn = {1743-0003},
year = {2022},
date = {2022-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {19},
number = {1},
address = {M. Ernst, Research Biomechanics, CR&S, Ottobock SE & Co. KGaA, Göttingen, Germany},
abstract = {Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.
Pröbsting, E.; Altenburg, B.; Bellmann, M.; Krug, K.; Schmalz, T.
In: Prosthet. Orthot. Int., Bd. 46, Nr. 4, S. 306–313, 2022, ISSN: 0309-3646.
@article{Proebsting2022,
title = {How does ankle power on the prosthetic side influence loading parameters on the sound side during level walking of persons with transfemoral amputation?},
author = {E. Pröbsting and B. Altenburg and M. Bellmann and K. Krug and T. Schmalz},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2019708323&from=export},
doi = {10.1097/pxr.0000000000000099},
issn = {0309-3646},
year = {2022},
date = {2022-01-01},
journal = {Prosthet. Orthot. Int.},
volume = {46},
number = {4},
pages = {306–313},
address = {E. Pröbsting, Ottobock SE & Co. KGaA, Herrmann-Rein-Straße 2a, Göttingen, Germany},
abstract = {Background:Increased ankle power on the prosthetic side seems to decrease biomechanical loading parameters on the sound side. This assumption is based on biomechanical comparisons of different foot constructions. However, such study designs could not show whether the amount of ankle power solely influences the sound side.Objective:To analyze the influence of divergent ankle power, resulting from different foot constructions and from different ankle power settings, on the sound side loading parameters.Study design:Interventional cross sectional study.Methods:Level walking of transfemoral amputees with a microprocessor knee joint and Solid Ankle Cushioned Heel (SACH), energy storing and returning (ESR) and powered foot (PF) was analyzed. The PF was adapted in three configurations: without power (np), low power (lp), and optimal power (op). An optoelectronic camera system with 12 cameras and two force plates were used.Results:The ankle power on the prosthetic side shows significant differences about foot types and different settings of the PF. The knee adduction moment, the knee flexion moment, and the vertical ground reaction forces on the sound side were significantly reduced with PF_op and ESR in comparison to SACH. When analyzing these parameters for the different PF configurations, only some show significant results at normal velocity.Conclusions:The additional positive mechanical work for an active push off in the PF tends to have a relieving effect. The biomechanical sound side loading parameters are reduced with PF_op in comparison to SACH and ESR, resulting in a relief of the sound side of lower limb amputees.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background:Increased ankle power on the prosthetic side seems to decrease biomechanical loading parameters on the sound side. This assumption is based on biomechanical comparisons of different foot constructions. However, such study designs could not show whether the amount of ankle power solely influences the sound side.Objective:To analyze the influence of divergent ankle power, resulting from different foot constructions and from different ankle power settings, on the sound side loading parameters.Study design:Interventional cross sectional study.Methods:Level walking of transfemoral amputees with a microprocessor knee joint and Solid Ankle Cushioned Heel (SACH), energy storing and returning (ESR) and powered foot (PF) was analyzed. The PF was adapted in three configurations: without power (np), low power (lp), and optimal power (op). An optoelectronic camera system with 12 cameras and two force plates were used.Results:The ankle power on the prosthetic side shows significant differences about foot types and different settings of the PF. The knee adduction moment, the knee flexion moment, and the vertical ground reaction forces on the sound side were significantly reduced with PF_op and ESR in comparison to SACH. When analyzing these parameters for the different PF configurations, only some show significant results at normal velocity.Conclusions:The additional positive mechanical work for an active push off in the PF tends to have a relieving effect. The biomechanical sound side loading parameters are reduced with PF_op in comparison to SACH and ESR, resulting in a relief of the sound side of lower limb amputees.
2021
Köhler, T. M.; Blumentritt, S.; Braatz, F.; Bellmann, M.
In: Gait Posture, Bd. 89, S. 169–177, 2021, ISSN: 0966-6362.
@article{Koehler2021,
title = {The impact of transfemoral socket adduction on pelvic and trunk stabilization during level walking - A biomechanical study},
author = {T. M. Köhler and S. Blumentritt and F. Braatz and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2013710687&from=export},
doi = {10.1016/j.gaitpost.2021.06.024},
issn = {0966-6362},
year = {2021},
date = {2021-09-01},
journal = {Gait Posture},
volume = {89},
pages = {169–177},
publisher = {Elsevier BV},
address = {T.M. Köhler, Ottobock SE & Co. KGaA, Hermann-Rein-Straße 2a, Göttingen, Germany},
abstract = {Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.
Waterval, N. F. J.; Brehm, M. -A.; Harlaar, J.; Nollet, F.
In: J. NeuroEng. Rehabil., Bd. 18, Nr. 1, 2021, ISSN: 1743-0003.
@article{Waterval2021,
title = {Individual stiffness optimization of dorsal leaf spring ankle-foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations},
author = {N. F. J. Waterval and M. -A. Brehm and J. Harlaar and F. Nollet},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2012344314&from=export},
doi = {10.1186/s12984-021-00890-8},
issn = {1743-0003},
year = {2021},
date = {2021-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {18},
number = {1},
address = {N.F.J. Waterval, Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, Netherlands},
abstract = {Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s
Yazdani, M.; Hajiaghaei, B.; Saeedi, H.; Kamali, M.; Yousefi, M.
In: Curr. Orthop. Pract., Bd. 32, Nr. 5, S. 505–511, 2021, ISSN: 1940-7041.
@article{Yazdani2021,
title = {Does the socket design affect symmetry and spatiotemporal gait parameters? A case series of two transfemoral amputees},
author = {M. Yazdani and B. Hajiaghaei and H. Saeedi and M. Kamali and M. Yousefi},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L635549609&from=export},
doi = {10.1097/bco.0000000000001022},
issn = {1940-7041},
year = {2021},
date = {2021-01-01},
journal = {Curr. Orthop. Pract.},
volume = {32},
number = {5},
pages = {505–511},
address = {B. Hajiaghaei, Department of Orthotics and Prosthetics, School of Rehabilitation Sciences, Iran University of Medical Sciences, Nezam Ave, Tehran, Iran},
abstract = {Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.
2020
Ernst, M.; Altenburg, B.; Schmalz, T.
Characterizing adaptations of prosthetic feet in the frontal plane Artikel
In: Prosthet. Orthot. Int., Bd. 44, Nr. 4, S. 225–233, 2020, ISSN: 0309-3646.
@article{Ernst2020,
title = {Characterizing adaptations of prosthetic feet in the frontal plane},
author = {M. Ernst and B. Altenburg and T. Schmalz},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2005154580&from=export},
doi = {10.1177/0309364620917838},
issn = {0309-3646},
year = {2020},
date = {2020-01-01},
journal = {Prosthet. Orthot. Int.},
volume = {44},
number = {4},
pages = {225–233},
address = {M. Ernst, Research Biomechanics, Clinical Research and Services, Ottobock SE Co. KGaA, Göttingen, Germany},
abstract = {Background: Energy-storage and return feet incorporate various design features including split toes. As a potential improvement, an energy-storage and return foot with a dedicated ankle joint was recently introduced allowing for easily accessible inversion/eversion movement. However, the adaptability of energy-storage and return feet to uneven ground and the effects on biomechanical and clinical parameters have not been investigated in detail. Objectives: To investigate the design-related ability of prosthetic feet to adapt to cross slopes and derive a theoretical model. Study design: Mechanical testing and characterization. Methods: Mechanical adaptation to cross slopes was investigated for six prosthetic feet measured by a motion capture system. A theoretical model linking the measured data with adaptations is proposed. Results: The type and degree of adaptation depends on the foot design, for example, stiffness, split toe or continuous carbon forefoot, and additional ankle joint. The model used shows high correlations with the measured data for all feet. Conclusions: The ability of prosthetic feet to adapt to uneven ground is design-dependent. The split-toe feet adapted better to cross slopes than those with continuous carbon forefeet. Joints enhance this further by allowing for additional inversion and eversion. The influence on biomechanical and clinical parameters should be assessed in future studies. Clinical relevance: Knowing foot-specific ability to adapt to uneven ground may help in selecting an appropriate prosthetic foot for persons with a lower limb amputation. Faster and more comprehensive adaptations to uneven ground may lower the need for compensations and therefore increase user safety.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Energy-storage and return feet incorporate various design features including split toes. As a potential improvement, an energy-storage and return foot with a dedicated ankle joint was recently introduced allowing for easily accessible inversion/eversion movement. However, the adaptability of energy-storage and return feet to uneven ground and the effects on biomechanical and clinical parameters have not been investigated in detail. Objectives: To investigate the design-related ability of prosthetic feet to adapt to cross slopes and derive a theoretical model. Study design: Mechanical testing and characterization. Methods: Mechanical adaptation to cross slopes was investigated for six prosthetic feet measured by a motion capture system. A theoretical model linking the measured data with adaptations is proposed. Results: The type and degree of adaptation depends on the foot design, for example, stiffness, split toe or continuous carbon forefoot, and additional ankle joint. The model used shows high correlations with the measured data for all feet. Conclusions: The ability of prosthetic feet to adapt to uneven ground is design-dependent. The split-toe feet adapted better to cross slopes than those with continuous carbon forefeet. Joints enhance this further by allowing for additional inversion and eversion. The influence on biomechanical and clinical parameters should be assessed in future studies. Clinical relevance: Knowing foot-specific ability to adapt to uneven ground may help in selecting an appropriate prosthetic foot for persons with a lower limb amputation. Faster and more comprehensive adaptations to uneven ground may lower the need for compensations and therefore increase user safety.
Hahne, J. M.; Wilke, M. A.; Koppe, M.; Farina, D.; Schilling, A. F.
Longitudinal Case Study of Regression-Based Hand Prosthesis Control in Daily Life Artikel
In: Front. Neurosci., Bd. 14, 2020, ISSN: 1662-4548.
@article{Hahne2020,
title = {Longitudinal Case Study of Regression-Based Hand Prosthesis Control in Daily Life},
author = {J. M. Hahne and M. A. Wilke and M. Koppe and D. Farina and A. F. Schilling},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L632229544&from=export},
doi = {10.3389/fnins.2020.00600},
issn = {1662-4548},
year = {2020},
date = {2020-01-01},
journal = {Front. Neurosci.},
volume = {14},
address = {J.M. Hahne, Applied Rehabilitation Technology Lab, Department of Trauma Surgery, Orthopedic Surgery and Hand Surgery, University Medical Center Göttingen, Göttingen, Germany},
abstract = {Hand prostheses are usually controlled by electromyographic (EMG) signals from the remnant muscles of the residual limb. Most prostheses used today are controlled with very simple techniques using only two EMG electrodes that allow to control a single prosthetic function at a time only. Recently, modern prosthesis controllers based on EMG classification, have become clinically available, which allow to directly access more functions, but still in a sequential manner only. We have recently shown in laboratory tests that a regression-based mapping from EMG signals into prosthetic control commands allows for a simultaneous activation of two functions and an independent control of their velocities with high reliability. Here we aimed to study how such regression-based control performs in daily life in a two-month case study. The performance is evaluated in functional tests and with a questionnaire at the beginning and the end of this phase and compared with the participant’s own prosthesis, controlled with a classical approach. Already 1 day after training of the regression model, the participant with transradial amputation outperformed the performance achieved with his own Michelangelo hand in two out of three functional metrics. No retraining of the model was required during the entire study duration. During the use of the system at home, the performance improved further and outperformed the conventional control in all three metrics. This study demonstrates that the high fidelity of linear regression-based prosthesis control is not restricted to a laboratory environment, but can be transferred to daily use.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Hand prostheses are usually controlled by electromyographic (EMG) signals from the remnant muscles of the residual limb. Most prostheses used today are controlled with very simple techniques using only two EMG electrodes that allow to control a single prosthetic function at a time only. Recently, modern prosthesis controllers based on EMG classification, have become clinically available, which allow to directly access more functions, but still in a sequential manner only. We have recently shown in laboratory tests that a regression-based mapping from EMG signals into prosthetic control commands allows for a simultaneous activation of two functions and an independent control of their velocities with high reliability. Here we aimed to study how such regression-based control performs in daily life in a two-month case study. The performance is evaluated in functional tests and with a questionnaire at the beginning and the end of this phase and compared with the participant’s own prosthesis, controlled with a classical approach. Already 1 day after training of the regression model, the participant with transradial amputation outperformed the performance achieved with his own Michelangelo hand in two out of three functional metrics. No retraining of the model was required during the entire study duration. During the use of the system at home, the performance improved further and outperformed the conventional control in all three metrics. This study demonstrates that the high fidelity of linear regression-based prosthesis control is not restricted to a laboratory environment, but can be transferred to daily use.
Taboga, P.; Beck, O. N.; Grabowski, A. M.
In: PLoS ONE, Bd. 15, Nr. 2, 2020, ISSN: 1932-6203.
@article{Taboga2020,
title = {Prosthetic shape, but not stiffness or height, affects the maximum speed of sprinters with bilateral transtibial amputations},
author = {P. Taboga and O. N. Beck and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2005026109&from=export},
doi = {10.1371/journal.pone.0229035},
issn = {1932-6203},
year = {2020},
date = {2020-01-01},
journal = {PLoS ONE},
volume = {15},
number = {2},
address = {P. Taboga, Department of Kinesiology, California State University, Sacramento, CA, United States},
abstract = {Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.
2019
Schmalz, T.; Schändlinger, J.; Schuler, M.; Bornmann, J.; Schirrmeister, B.; Kannenberg, A.; Ernst, M.
Biomechanical and metabolic effectiveness of an industrial exoskeleton for overhead work Artikel
In: Int. J. Environ. Res. Public Health, Bd. 16, Nr. 23, 2019, ISSN: 1661-7827.
@article{Schmalz2019,
title = {Biomechanical and metabolic effectiveness of an industrial exoskeleton for overhead work},
author = {T. Schmalz and J. Schändlinger and M. Schuler and J. Bornmann and B. Schirrmeister and A. Kannenberg and M. Ernst},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2003259386&from=export},
doi = {10.3390/ijerph16234792},
issn = {1661-7827},
year = {2019},
date = {2019-01-01},
journal = {Int. J. Environ. Res. Public Health},
volume = {16},
number = {23},
address = {T. Schmalz, Clinical Research & Services/Biomechanics, Otto Bock SE & Co. KGaA, Göttingen, Germany},
abstract = {Overhead work activities can lead to shoulder pain and serious musculoskeletal disorders (WMSD), such as rotator cuff injury and degeneration. Recently developed exoskeletons show promising results in supporting workers in such activities. In this study, a novel exoskeleton was investigated for two different overhead tasks with twelve participants. To investigate the effects of the device, electromyographic (EMG) signals of different shoulder and adjacent muscles as well as kinematic and metabolic parameters were analyzed with and without the exoskeleton. The mean EMG amplitude of all evaluated muscles was significantly reduced when the exoskeleton was used for the overhead tasks. This was accompanied by a reduction in both heart rate and oxygen rate. The kinematic analysis revealed small changes in the joint positions during the tasks. This study demonstrated the biomechanical and metabolic benefits of an exoskeleton designed to support overhead work activities. The results suggest improved physiological conditions and an unloading effect on the shoulder joint and muscles which are promising indicators that the exoskeleton may be a good solution to reduce shoulder WMSD among workers who carry out overhead tasks on a regular basis.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Overhead work activities can lead to shoulder pain and serious musculoskeletal disorders (WMSD), such as rotator cuff injury and degeneration. Recently developed exoskeletons show promising results in supporting workers in such activities. In this study, a novel exoskeleton was investigated for two different overhead tasks with twelve participants. To investigate the effects of the device, electromyographic (EMG) signals of different shoulder and adjacent muscles as well as kinematic and metabolic parameters were analyzed with and without the exoskeleton. The mean EMG amplitude of all evaluated muscles was significantly reduced when the exoskeleton was used for the overhead tasks. This was accompanied by a reduction in both heart rate and oxygen rate. The kinematic analysis revealed small changes in the joint positions during the tasks. This study demonstrated the biomechanical and metabolic benefits of an exoskeleton designed to support overhead work activities. The results suggest improved physiological conditions and an unloading effect on the shoulder joint and muscles which are promising indicators that the exoskeleton may be a good solution to reduce shoulder WMSD among workers who carry out overhead tasks on a regular basis.
Volkmar, R.; Dosen, S.; Gonzalez-Vargas, J.; Baum, M.; Markovic, M.
Improving bimanual interaction with a prosthesis using semi-autonomous control Artikel
In: J. NeuroEng. Rehabil., Bd. 16, Nr. 1, 2019, ISSN: 1743-0003.
@article{Volkmar2019,
title = {Improving bimanual interaction with a prosthesis using semi-autonomous control},
author = {R. Volkmar and S. Dosen and J. Gonzalez-Vargas and M. Baum and M. Markovic},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L629849607&from=export},
doi = {10.1186/s12984-019-0617-6},
issn = {1743-0003},
year = {2019},
date = {2019-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {16},
number = {1},
address = {M. Markovic, Department of Trauma Surgery Orthopedics and Plastic Surgery, University Medical Center Göttingen, Von-Siebold-Str. 3, Göttingen, Germany},
abstract = {Background: The loss of a hand is a traumatic experience that substantially compromises an individual's capability to interact with his environment. The myoelectric prostheses are state-of-the-art (SoA) functional replacements for the lost limbs. Their overall mechanical design and dexterity have improved over the last few decades, but the users have not been able to fully exploit these advances because of the lack of effective and intuitive control. Bimanual tasks are particularly challenging for an amputee since prosthesis control needs to be coordinated with the movement of the sound limb. So far, the bimanual activities have been often neglected by the prosthetic research community. Methods: We present a novel method to prosthesis control, which uses a semi-autonomous approach in order to simplify bimanual interactions. The approach supplements the commercial SoA two-channel myoelectric control with two additional sensors. Two inertial measurement units were attached to the prosthesis and the sound hand to detect the movement of both limbs. Once a bimanual interaction is detected, the system mimics the coordination strategies of able-bodied subjects to automatically adjust the prosthesis wrist rotation (pronation, supination) and grip type (lateral, palmar) to assist the sound hand during a bimanual task. The system has been evaluated in eight able-bodied subjects performing functional uni- A nd bi-manual tasks using the novel method and SoA two-channel myocontrol. The outcome measures were time to accomplish the task, semi-autonomous system misclassification rate, subjective rating of intuitiveness, and perceived workload (NASA TLX). Results: The results demonstrated that the novel control interface substantially outperformed the SoA myoelectric control. While using the semi-autonomous control the time to accomplish the task and the perceived workload decreased for 25 and 27%, respectively, while the subjects rated the system as more intuitive then SoA myocontrol. Conclusions: The novel system uses minimal additional hardware (two inertial sensors) and simple processing and it is therefore convenient for practical implementation. By using the proposed control scheme, the prosthesis assists the user's sound hand in performing bimanual interactions while decreasing cognitive burden.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: The loss of a hand is a traumatic experience that substantially compromises an individual's capability to interact with his environment. The myoelectric prostheses are state-of-the-art (SoA) functional replacements for the lost limbs. Their overall mechanical design and dexterity have improved over the last few decades, but the users have not been able to fully exploit these advances because of the lack of effective and intuitive control. Bimanual tasks are particularly challenging for an amputee since prosthesis control needs to be coordinated with the movement of the sound limb. So far, the bimanual activities have been often neglected by the prosthetic research community. Methods: We present a novel method to prosthesis control, which uses a semi-autonomous approach in order to simplify bimanual interactions. The approach supplements the commercial SoA two-channel myoelectric control with two additional sensors. Two inertial measurement units were attached to the prosthesis and the sound hand to detect the movement of both limbs. Once a bimanual interaction is detected, the system mimics the coordination strategies of able-bodied subjects to automatically adjust the prosthesis wrist rotation (pronation, supination) and grip type (lateral, palmar) to assist the sound hand during a bimanual task. The system has been evaluated in eight able-bodied subjects performing functional uni- A nd bi-manual tasks using the novel method and SoA two-channel myocontrol. The outcome measures were time to accomplish the task, semi-autonomous system misclassification rate, subjective rating of intuitiveness, and perceived workload (NASA TLX). Results: The results demonstrated that the novel control interface substantially outperformed the SoA myoelectric control. While using the semi-autonomous control the time to accomplish the task and the perceived workload decreased for 25 and 27%, respectively, while the subjects rated the system as more intuitive then SoA myocontrol. Conclusions: The novel system uses minimal additional hardware (two inertial sensors) and simple processing and it is therefore convenient for practical implementation. By using the proposed control scheme, the prosthesis assists the user's sound hand in performing bimanual interactions while decreasing cognitive burden.
Webster, J. B.
Lower Limb Amputation Care Across the Active Duty Military and Veteran Populations Artikel
In: Phys. Med. Rehabil. Clin. North Am., Bd. 30, Nr. 1, S. 89–109, 2019, ISSN: 1047-9651.
@article{Webster2019,
title = {Lower Limb Amputation Care Across the Active Duty Military and Veteran Populations},
author = {J. B. Webster},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2001229794&from=export},
doi = {10.1016/j.pmr.2018.08.008},
issn = {1047-9651},
year = {2019},
date = {2019-01-01},
journal = {Phys. Med. Rehabil. Clin. North Am.},
volume = {30},
number = {1},
pages = {89–109},
abstract = {Traumatic amputation can result from injuries sustained both within and outside the military setting. Individuals with trauma-related amputations have unique needs and require specialized management with an interdisciplinary team approach and care coordination across the continuum of care to facilitate optimal outcomes. Management considerations include issues with the amputation itself, issues related to injury of other body parts, and the management of longer-term secondary conditions. Some of these issues are more prevalent and of greater severity in the early recovery period, whereas others develop later and have the potential for progressive worsening over time.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Traumatic amputation can result from injuries sustained both within and outside the military setting. Individuals with trauma-related amputations have unique needs and require specialized management with an interdisciplinary team approach and care coordination across the continuum of care to facilitate optimal outcomes. Management considerations include issues with the amputation itself, issues related to injury of other body parts, and the management of longer-term secondary conditions. Some of these issues are more prevalent and of greater severity in the early recovery period, whereas others develop later and have the potential for progressive worsening over time.
2018
Houdijk, H.; Wezenberg, D.; Hak, L.; Cutti, A. G.
In: J. NeuroEng. Rehabil., Bd. 15, 2018, ISSN: 1743-0003.
@article{Houdijk2018,
title = {Energy storing and return prosthetic feet improve step length symmetry while preserving margins of stability in persons with transtibial amputation},
author = {H. Houdijk and D. Wezenberg and L. Hak and A. G. Cutti},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L623754871&from=export},
doi = {10.1186/s12984-018-0404-9},
issn = {1743-0003},
year = {2018},
date = {2018-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {15},
address = {H. Houdijk, Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, Vrije Universiteit Amsterdam, Van der Boechorststraat 9, Amsterdam, Netherlands},
abstract = {Background: Energy storing and return (ESAR) feet are generally preferred over solid ankle cushioned heel (SACH) feet by people with a lower limb amputation. While ESAR feet have been shown to have only limited effect on gait economy, other functional benefits should account for this preference. A simple biomechanical model suggests that enhanced gait stability and gait symmetry could prove to explain part of the difference in the subjective preference between both feet. Aim: To investigate whether increased push-off power with ESAR feet increases center of mass velocity at push off and enhance intact step length and step length symmetry while preserving the margin of stability during walking in people with a transtibial prosthesis. Methods: Fifteen people with a unilateral transtibial amputation walked with their prescribed ESAR foot and a SACH foot at a fixed walking speed (1.2 m/s) over a level walkway while kinematic and kinetic data were collected. Push-off work generated by the foot, center of mass velocity, step length, step length symmetry and backward margin of stability were assessed and compared between feet. Results: Push-off work was significantly higher when using the ESAR foot compared to the SACH foot. Simultaneously, center of mass velocity at toe-off was higher with ESAR compared to SACH, and intact step length and step length symmetry increased without reducing the backward margin of stability. Conclusion: Compared to the SACH foot, the ESAR foot allowed an improvement of step length symmetry while preserving the backward margin of stability at community ambulation speed. These benefits may possibly contribute to the subjective preference for ESAR feet in people with a lower limb amputation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Energy storing and return (ESAR) feet are generally preferred over solid ankle cushioned heel (SACH) feet by people with a lower limb amputation. While ESAR feet have been shown to have only limited effect on gait economy, other functional benefits should account for this preference. A simple biomechanical model suggests that enhanced gait stability and gait symmetry could prove to explain part of the difference in the subjective preference between both feet. Aim: To investigate whether increased push-off power with ESAR feet increases center of mass velocity at push off and enhance intact step length and step length symmetry while preserving the margin of stability during walking in people with a transtibial prosthesis. Methods: Fifteen people with a unilateral transtibial amputation walked with their prescribed ESAR foot and a SACH foot at a fixed walking speed (1.2 m/s) over a level walkway while kinematic and kinetic data were collected. Push-off work generated by the foot, center of mass velocity, step length, step length symmetry and backward margin of stability were assessed and compared between feet. Results: Push-off work was significantly higher when using the ESAR foot compared to the SACH foot. Simultaneously, center of mass velocity at toe-off was higher with ESAR compared to SACH, and intact step length and step length symmetry increased without reducing the backward margin of stability. Conclusion: Compared to the SACH foot, the ESAR foot allowed an improvement of step length symmetry while preserving the backward margin of stability at community ambulation speed. These benefits may possibly contribute to the subjective preference for ESAR feet in people with a lower limb amputation.
2017
Ernst, M.; Altenburg, B.; Bellmann, M.; Schmalz, T.
In: J. NeuroEng. Rehabil., Bd. 14, Nr. 1, 2017, ISSN: 1743-0003.
@article{Ernst2017,
title = {Standing on slopes - How current microprocessor-controlled prosthetic feet support transtibial and transfemoral amputees in an everyday task},
author = {M. Ernst and B. Altenburg and M. Bellmann and T. Schmalz},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L619264869&from=export},
doi = {10.1186/s12984-017-0322-2},
issn = {1743-0003},
year = {2017},
date = {2017-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {14},
number = {1},
address = {M. Ernst, Research Biomechanics, CRandS, Otto Bock HealthCare GmbH, Göttingen, Germany},
abstract = {Background: Conventional prosthetic feet like energy storage and return feet provide only a limited range of ankle motion compared to human ones. In order to overcome the poor rotational adaptability, prosthetic manufacturers developed different prosthetic feet with an additional rotational joint and implemented active control in different states. It was the aim of the study to investigate to what extent these commercially available microprocessor-controlled prosthetic feet support a natural posture while standing on inclines and which concept is most beneficial for lower limb amputees. Methods: Four unilateral transtibial and four unilateral transfemoral amputees participated in the study. Each of the subjects wore five different microprocessor-controlled prosthetic feet in addition to their everyday feet. The subjects were asked to stand on slopes of different inclinations (level ground, upward slope of 10°, and downward slope of -10°). Vertical ground reaction forces, joint torques and joint angles in the sagittal plane were measured for both legs separately for the different situations and compared to a non-amputee reference group. Results: Differences in the biomechanical parameters were observed between the different prosthetic feet and compared to the reference group for the investigated situations. They were most prominent while standing on a downward slope. For example, on the prosthetic side, the vertical ground reaction force is reduced by about 20%, and the torque about the knee acts to flex the joint for feet that are not capable of a full adaptation to the downward slope. In contrast, fully adaptable feet with an auto-adaptive dorsiflexion stop show no changes in vertical ground reaction forces and knee extending torques. Conclusions: A prosthetic foot that provides both, an auto-adaptive dorsiflexion stop and a sufficient range of motion for fully adapting to inclinations appears to be the key element in the prosthetic fitting for standing on inclinations in lower limb amputees. In such situations, this prosthetic concept appears superior to both, conventional feet with passive structures as well as feet that solely provide a sufficient range of motion. The results also indicate that both, transfemoral and transtibial amputees benefit from such a foot.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Conventional prosthetic feet like energy storage and return feet provide only a limited range of ankle motion compared to human ones. In order to overcome the poor rotational adaptability, prosthetic manufacturers developed different prosthetic feet with an additional rotational joint and implemented active control in different states. It was the aim of the study to investigate to what extent these commercially available microprocessor-controlled prosthetic feet support a natural posture while standing on inclines and which concept is most beneficial for lower limb amputees. Methods: Four unilateral transtibial and four unilateral transfemoral amputees participated in the study. Each of the subjects wore five different microprocessor-controlled prosthetic feet in addition to their everyday feet. The subjects were asked to stand on slopes of different inclinations (level ground, upward slope of 10°, and downward slope of -10°). Vertical ground reaction forces, joint torques and joint angles in the sagittal plane were measured for both legs separately for the different situations and compared to a non-amputee reference group. Results: Differences in the biomechanical parameters were observed between the different prosthetic feet and compared to the reference group for the investigated situations. They were most prominent while standing on a downward slope. For example, on the prosthetic side, the vertical ground reaction force is reduced by about 20%, and the torque about the knee acts to flex the joint for feet that are not capable of a full adaptation to the downward slope. In contrast, fully adaptable feet with an auto-adaptive dorsiflexion stop show no changes in vertical ground reaction forces and knee extending torques. Conclusions: A prosthetic foot that provides both, an auto-adaptive dorsiflexion stop and a sufficient range of motion for fully adapting to inclinations appears to be the key element in the prosthetic fitting for standing on inclinations in lower limb amputees. In such situations, this prosthetic concept appears superior to both, conventional feet with passive structures as well as feet that solely provide a sufficient range of motion. The results also indicate that both, transfemoral and transtibial amputees benefit from such a foot.
Shimizu, Y.; Mutsuzaki, H.; Maezawa, T.; Idei, Y.; Takao, K.; Takeuchi, R.; Onishi, S.; Hada, Y.; Yamazaki, M.; Wadano, Y.
In: Prosthet. Orthot. Int., Bd. 41, Nr. 5, S. 522–526, 2017, ISSN: 0309-3646.
@article{Shimizu2017,
title = {Hip prosthesis in sitting posture for bilateral transfemoral amputee after burn injury: a case report},
author = {Y. Shimizu and H. Mutsuzaki and T. Maezawa and Y. Idei and K. Takao and R. Takeuchi and S. Onishi and Y. Hada and M. Yamazaki and Y. Wadano},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L618507994&from=export},
doi = {10.1177/0309364616682384},
issn = {0309-3646},
year = {2017},
date = {2017-01-01},
journal = {Prosthet. Orthot. Int.},
volume = {41},
number = {5},
pages = {522–526},
address = {Y. Shimizu, Department of Rehabilitation Medicine, University of Tsukuba Hospital, 2-1-1, Amakubo, Tsukuba, Ibaraki, Japan},
abstract = {Background: To overcome the challenges of rehabilitation of bilateral transfemoral amputees, we developed a novel “hip prosthesis in the sitting posture.” Case Description and Methods: A 64-year-old male bilateral transfemoral amputee was transferred for rehabilitation 4 months following a burn injury. His wounds remained unhealed for 20 months; thus, he was unable to participate in standing training with the standard prosthetic sockets. Hip prosthesis in the sitting posture has very little friction between the sockets and residual limbs, which facilitated our patient to begin standing and walking exercises. Findings and Outcomes: The patient’s refractory wounds healed 1 month after initiating exercises using hip prosthesis in the sitting posture, and he could begin rehabilitation with the standard prostheses. Discussion and Conclusion: Hip prosthesis in the sitting posture enabled a bilateral transfemoral amputee with unhealed residual limbs to stand, walk, and begin balance training. Hip prosthesis in the sitting posture is an effective temporary prosthesis to prevent disuse until wounds are healed and to continue rehabilitation with standard prostheses. Clinical relevance: Hip prosthesis in the sitting posture is useful for bilateral transfemoral amputees with unhealed residual limbs after burn injuries to prevent disuse and maintain motivation for walking.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: To overcome the challenges of rehabilitation of bilateral transfemoral amputees, we developed a novel “hip prosthesis in the sitting posture.” Case Description and Methods: A 64-year-old male bilateral transfemoral amputee was transferred for rehabilitation 4 months following a burn injury. His wounds remained unhealed for 20 months; thus, he was unable to participate in standing training with the standard prosthetic sockets. Hip prosthesis in the sitting posture has very little friction between the sockets and residual limbs, which facilitated our patient to begin standing and walking exercises. Findings and Outcomes: The patient’s refractory wounds healed 1 month after initiating exercises using hip prosthesis in the sitting posture, and he could begin rehabilitation with the standard prostheses. Discussion and Conclusion: Hip prosthesis in the sitting posture enabled a bilateral transfemoral amputee with unhealed residual limbs to stand, walk, and begin balance training. Hip prosthesis in the sitting posture is an effective temporary prosthesis to prevent disuse until wounds are healed and to continue rehabilitation with standard prostheses. Clinical relevance: Hip prosthesis in the sitting posture is useful for bilateral transfemoral amputees with unhealed residual limbs after burn injuries to prevent disuse and maintain motivation for walking.
Rigney, S. M.; Simmons, A.; Kark, L.
Mechanical characterization and comparison of energy storage and return prostheses Artikel
In: Med. Eng. Phys., Bd. 41, S. 90–96, 2017, ISSN: 1350-4533.
@article{Rigney2017,
title = {Mechanical characterization and comparison of energy storage and return prostheses},
author = {S. M. Rigney and A. Simmons and L. Kark},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L614136635&from=export},
doi = {10.1016/j.medengphy.2017.01.003},
issn = {1350-4533},
year = {2017},
date = {2017-01-01},
journal = {Med. Eng. Phys.},
volume = {41},
pages = {90–96},
address = {L. Kark, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia},
abstract = {The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.
Dosen, S.; Markovic, M.; Strbac, M.; Belic, M.; Kojic, V.; Bijelic, G.; Keller, T.; Farina, D.
In: IEEE Trans. Neural Syst. Rehabil. Eng., Bd. 25, Nr. 3, S. 183–195, 2017, ISSN: 1534-4320.
@article{Dosen2017,
title = {Multichannel electrotactile feedback with spatial and mixed coding for closed-loop control of grasping force in hand prostheses},
author = {S. Dosen and M. Markovic and M. Strbac and M. Belic and V. Kojic and G. Bijelic and T. Keller and D. Farina},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L615004930&from=export},
doi = {10.1109/tnsre.2016.2550864},
issn = {1534-4320},
year = {2017},
date = {2017-01-01},
journal = {IEEE Trans. Neural Syst. Rehabil. Eng.},
volume = {25},
number = {3},
pages = {183–195},
abstract = {Providing somatosensory feedback to the user of a myoelectric prosthesis is an important goal since it can improve the utility as well as facilitate the embodiment of the assistive system. Most often, the grasping force was selected as the feedback variable and communicated through one or more individual single channel stimulation units (e.g., electrodes, vibration motors). In the present study, an integrated, compact, multichannel solution comprising an array electrode and a programmable stimulator was presented. Two coding schemes (15 levels), spatial and mixed (spatial and frequency) modulation, were tested in able-bodied subjects, psychometrically and in force control with routine grasping and force tracking using real and simulated prosthesis. The results demonstrated that mixed and spatial coding, although substantially different in psychometric tests, resulted in a similar performance during both force control tasks. Furthermore, the ideal, visual feedback was not better than the tactile feedback in routine grasping. To explain the observed results, a conceptual model was proposed emphasizing that the performance depends on multiple factors, including feedback uncertainty, nature of the task and the reliability of the feedforward control. The study outcomes, specific conclusions and the general model, are relevant for the design of closed-loop myoelectric prostheses utilizing tactile feedback.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Providing somatosensory feedback to the user of a myoelectric prosthesis is an important goal since it can improve the utility as well as facilitate the embodiment of the assistive system. Most often, the grasping force was selected as the feedback variable and communicated through one or more individual single channel stimulation units (e.g., electrodes, vibration motors). In the present study, an integrated, compact, multichannel solution comprising an array electrode and a programmable stimulator was presented. Two coding schemes (15 levels), spatial and mixed (spatial and frequency) modulation, were tested in able-bodied subjects, psychometrically and in force control with routine grasping and force tracking using real and simulated prosthesis. The results demonstrated that mixed and spatial coding, although substantially different in psychometric tests, resulted in a similar performance during both force control tasks. Furthermore, the ideal, visual feedback was not better than the tactile feedback in routine grasping. To explain the observed results, a conceptual model was proposed emphasizing that the performance depends on multiple factors, including feedback uncertainty, nature of the task and the reliability of the feedforward control. The study outcomes, specific conclusions and the general model, are relevant for the design of closed-loop myoelectric prostheses utilizing tactile feedback.
Pröbsting, E.; Kannenberg, A.; Zacharias, B.
In: Prosthet. Orthot. Int., Bd. 41, Nr. 1, S. 65–77, 2017, ISSN: 0309-3646.
@article{Proebsting2017,
title = {Safety and walking ability of KAFO users with the C-Brace® Orthotronic Mobility System, a new microprocessor stance and swing control orthosis},
author = {E. Pröbsting and A. Kannenberg and B. Zacharias},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L614321344&from=export},
doi = {10.1177/0309364616637954},
issn = {0309-3646},
year = {2017},
date = {2017-01-01},
journal = {Prosthet. Orthot. Int.},
volume = {41},
number = {1},
pages = {65–77},
address = {E. Pröbsting, Otto Bock HealthCare GmbH, Department Clinical Research and Services, Goettingen, Germany},
abstract = {Background: There are clear indications for benefits of stance control orthoses compared to locked knee ankle foot orthoses. However, stance control orthoses still have limited function compared with a sound human leg. Objectives: The aim of this study was to evaluate the potential benefits of a microprocessor stance and swing control orthosis compared to stance control orthoses and locked knee ankle foot orthoses in activities of daily living. Study design: Survey of lower limb orthosis users before and after fitting of a microprocessor stance and swing control orthosis. Methods: Thirteen patients with various lower limb pareses completed a baseline survey for their current orthotic device (locked knee ankle foot orthosis or stance control orthosis) and a follow-up for the microprocessor stance and swing control orthosis with the Orthosis Evaluation Questionnaire, a new self-reported outcome measure devised by modifying the Prosthesis Evaluation Questionnaire for use in lower limb orthotics and the Activities of Daily Living Questionnaire. Results: The Orthosis Evaluation Questionnaire results demonstrated significant improvements by microprocessor stance and swing control orthosis use in the total score and the domains of ambulation (p =.001), paretic limb health (p =.04), sounds (p =.02), and well-being (p =.01). Activities of Daily Living Questionnaire results showed significant improvements with the microprocessor stance and swing control orthosis with regard to perceived safety and difficulty of activities of daily living. Conclusion: The microprocessor stance and swing control orthosis may facilitate an easier, more physiological, and safer execution of many activities of daily living compared to traditional leg orthosis technologies. Clinical relevance This study compared patient-reported outcomes of a microprocessor stance and swing control orthosis (C-Brace) to those with traditional knee ankle foot orthosis and stance control orthosis devices. The C-Brace offers new functions including controlled knee flexion during weight bearing and dynamic swing control, resulting in significant improvements in perceived orthotic mobility and safety.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: There are clear indications for benefits of stance control orthoses compared to locked knee ankle foot orthoses. However, stance control orthoses still have limited function compared with a sound human leg. Objectives: The aim of this study was to evaluate the potential benefits of a microprocessor stance and swing control orthosis compared to stance control orthoses and locked knee ankle foot orthoses in activities of daily living. Study design: Survey of lower limb orthosis users before and after fitting of a microprocessor stance and swing control orthosis. Methods: Thirteen patients with various lower limb pareses completed a baseline survey for their current orthotic device (locked knee ankle foot orthosis or stance control orthosis) and a follow-up for the microprocessor stance and swing control orthosis with the Orthosis Evaluation Questionnaire, a new self-reported outcome measure devised by modifying the Prosthesis Evaluation Questionnaire for use in lower limb orthotics and the Activities of Daily Living Questionnaire. Results: The Orthosis Evaluation Questionnaire results demonstrated significant improvements by microprocessor stance and swing control orthosis use in the total score and the domains of ambulation (p =.001), paretic limb health (p =.04), sounds (p =.02), and well-being (p =.01). Activities of Daily Living Questionnaire results showed significant improvements with the microprocessor stance and swing control orthosis with regard to perceived safety and difficulty of activities of daily living. Conclusion: The microprocessor stance and swing control orthosis may facilitate an easier, more physiological, and safer execution of many activities of daily living compared to traditional leg orthosis technologies. Clinical relevance This study compared patient-reported outcomes of a microprocessor stance and swing control orthosis (C-Brace) to those with traditional knee ankle foot orthosis and stance control orthosis devices. The C-Brace offers new functions including controlled knee flexion during weight bearing and dynamic swing control, resulting in significant improvements in perceived orthotic mobility and safety.
2016
Beck, O. N.; Taboga, P.; Grabowski, A. M.
Characterizing the mechanical properties of running-specific prostheses Artikel
In: PLoS ONE, Bd. 11, Nr. 12, 2016, ISSN: 1932-6203.
@article{Beck2016,
title = {Characterizing the mechanical properties of running-specific prostheses},
author = {O. N. Beck and P. Taboga and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613668924&from=export},
doi = {10.1371/journal.pone.0168298},
issn = {1932-6203},
year = {2016},
date = {2016-01-01},
journal = {PLoS ONE},
volume = {11},
number = {12},
abstract = {The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.
Schweisfurth, M. A.; Markovic, M.; Dosen, S.; Teich, F.; Graimann, B.; Farina, D.
Electrotactile EMG feedback improves the control of prosthesis grasping force Artikel
In: J. Neural Eng., Bd. 13, Nr. 5, 2016, ISSN: 1741-2560.
@article{Schweisfurth2016,
title = {Electrotactile EMG feedback improves the control of prosthesis grasping force},
author = {M. A. Schweisfurth and M. Markovic and S. Dosen and F. Teich and B. Graimann and D. Farina},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L612465506&from=export},
doi = {10.1088/1741-2560/13/5/056010},
issn = {1741-2560},
year = {2016},
date = {2016-01-01},
journal = {J. Neural Eng.},
volume = {13},
number = {5},
address = {D. Farina, Institute for NeuroRehabilitation Systems, University Medical Center Göttingen, Georg-August University, Göttingen, Germany},
abstract = {Objective. A drawback of active prostheses is that they detach the subject from the produced forces, thereby preventing direct mechanical feedback. This can be compensated by providing somatosensory feedback to the user through mechanical or electrical stimulation, which in turn may improve the utility, sense of embodiment, and thereby increase the acceptance rate. Approach. In this study, we compared a novel approach to closing the loop, namely EMG feedback (emgFB), to classic force feedback (forceFB), using electrotactile interface in a realistic task setup. Eleven intact-bodied subjects and one transradial amputee performed a routine grasping task while receiving emgFB or forceFB. The two feedback types were delivered through the same electrotactile interface, using a mixed spatial/frequency coding to transmit 8 discrete levels of the feedback variable. In emgFB, the stimulation transmitted the amplitude of the processed myoelectric signal generated by the subject (prosthesis input), and in forceFB the generated grasping force (prosthesis output). The task comprised 150 trials of routine grasping at six forces, randomly presented in blocks of five trials (same force). Interquartile range and changes in the absolute error (AE) distribution (magnitude and dispersion) with respect to the target level were used to assess precision and overall performance, respectively. Main results. Relative to forceFB, emgFB significantly improved the precision of myoelectric commands (min/max of the significant levels) for 23%/36% as well as the precision of force control for 12%/32%, in intact-bodied subjects. Also, the magnitude and dispersion of the AE distribution were reduced. The results were similar in the amputee, showing considerable improvements. Significance. Using emgFB, the subjects therefore decreased the uncertainty of the forward pathway. Since there is a correspondence between the EMG and force, where the former anticipates the latter, the emgFB allowed for predictive control, as the subjects used the feedback to adjust the desired force even before the prosthesis contacted the object. In conclusion, the online emgFB was superior to the classic forceFB in realistic conditions that included electrotactile stimulation, limited feedback resolution (8 levels), cognitive processing delay, and time constraints (fast grasping).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objective. A drawback of active prostheses is that they detach the subject from the produced forces, thereby preventing direct mechanical feedback. This can be compensated by providing somatosensory feedback to the user through mechanical or electrical stimulation, which in turn may improve the utility, sense of embodiment, and thereby increase the acceptance rate. Approach. In this study, we compared a novel approach to closing the loop, namely EMG feedback (emgFB), to classic force feedback (forceFB), using electrotactile interface in a realistic task setup. Eleven intact-bodied subjects and one transradial amputee performed a routine grasping task while receiving emgFB or forceFB. The two feedback types were delivered through the same electrotactile interface, using a mixed spatial/frequency coding to transmit 8 discrete levels of the feedback variable. In emgFB, the stimulation transmitted the amplitude of the processed myoelectric signal generated by the subject (prosthesis input), and in forceFB the generated grasping force (prosthesis output). The task comprised 150 trials of routine grasping at six forces, randomly presented in blocks of five trials (same force). Interquartile range and changes in the absolute error (AE) distribution (magnitude and dispersion) with respect to the target level were used to assess precision and overall performance, respectively. Main results. Relative to forceFB, emgFB significantly improved the precision of myoelectric commands (min/max of the significant levels) for 23%/36% as well as the precision of force control for 12%/32%, in intact-bodied subjects. Also, the magnitude and dispersion of the AE distribution were reduced. The results were similar in the amputee, showing considerable improvements. Significance. Using emgFB, the subjects therefore decreased the uncertainty of the forward pathway. Since there is a correspondence between the EMG and force, where the former anticipates the latter, the emgFB allowed for predictive control, as the subjects used the feedback to adjust the desired force even before the prosthesis contacted the object. In conclusion, the online emgFB was superior to the classic forceFB in realistic conditions that included electrotactile stimulation, limited feedback resolution (8 levels), cognitive processing delay, and time constraints (fast grasping).
Williams, M. R.; D'Andrea, S.; Herr, H. M.
Impact on gait biomechanics of using an active variable impedance prosthetic knee Artikel
In: J. NeuroEng. Rehabil., Bd. 13, Nr. 1, 2016, ISSN: 1743-0003.
@article{Williams2016,
title = {Impact on gait biomechanics of using an active variable impedance prosthetic knee},
author = {M. R. Williams and S. D'Andrea and H. M. Herr},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L610660431&from=export},
doi = {10.1186/s12984-016-0159-0},
issn = {1743-0003},
year = {2016},
date = {2016-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {13},
number = {1},
address = {M.R. Williams, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States},
abstract = {Background: An above knee amputation can have a significant impact on gait, with substantial deviations in inter-leg symmetry, step length, hip exertion and upper body involvement even when using a current clinical standard of care prosthesis. These differences can produce gait that is less efficient and less comfortable, resulting in slower and shorter distance walking, particularly with long term use. Methods: A robotic variable impedance prosthetic knee (VI Knee) was tested with five individuals (N = 5) with unilateral amputation above the knee at fixed speeds both above and below their normal walking speed. Subject gait was measured as they walked along an instrumented walkway via optical motion capture and force plates in the floor. Each subject's gait while using the VI Knee was compared to that while using their standard of care knee (OttoBock C-Leg). Results: Significant differences (p < 0.05) in walking between the standard of care and variable impedance devices were seen in step length and hip range of motion symmetries, hip extension moment, knee power and torso lean angle. While using the VI Knee, several subjects demonstrated statistically significant improvements in gait, particularly in increased hip range of motion symmetry between affected and intact sides, greater prosthesis knee power and in reducing upper body involvement in the walking task by decreasing forward and affected side lean and reducing the pelvis-torso twist coupling. These changes to torso posture during gait also resulted in increased terminal stance hip flexion moment across subjects. Detriments to gait were also observed in that some subjects exhibited decreased step length symmetry while using the VI Knee compared to the C-Leg. Conclusions: The knee tested represents the potential to improve gait biomechanics and reduce upper body involvement in persons with above knee amputation compared to current standard of care devices. While using the VI Knee, subjects demonstrated statistically significant improvements in several aspects of gait though some were worsened while using the device. It is possible that these negative effects may be mitigated through longer term training and experience with the VI Knee. Given the demonstrated benefits and the potential to reduce or eliminate detriments through training, using a powered device like the VI Knee, particularly over an extended period of time, may help to improve walking performance and comfort.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: An above knee amputation can have a significant impact on gait, with substantial deviations in inter-leg symmetry, step length, hip exertion and upper body involvement even when using a current clinical standard of care prosthesis. These differences can produce gait that is less efficient and less comfortable, resulting in slower and shorter distance walking, particularly with long term use. Methods: A robotic variable impedance prosthetic knee (VI Knee) was tested with five individuals (N = 5) with unilateral amputation above the knee at fixed speeds both above and below their normal walking speed. Subject gait was measured as they walked along an instrumented walkway via optical motion capture and force plates in the floor. Each subject's gait while using the VI Knee was compared to that while using their standard of care knee (OttoBock C-Leg). Results: Significant differences (p < 0.05) in walking between the standard of care and variable impedance devices were seen in step length and hip range of motion symmetries, hip extension moment, knee power and torso lean angle. While using the VI Knee, several subjects demonstrated statistically significant improvements in gait, particularly in increased hip range of motion symmetry between affected and intact sides, greater prosthesis knee power and in reducing upper body involvement in the walking task by decreasing forward and affected side lean and reducing the pelvis-torso twist coupling. These changes to torso posture during gait also resulted in increased terminal stance hip flexion moment across subjects. Detriments to gait were also observed in that some subjects exhibited decreased step length symmetry while using the VI Knee compared to the C-Leg. Conclusions: The knee tested represents the potential to improve gait biomechanics and reduce upper body involvement in persons with above knee amputation compared to current standard of care devices. While using the VI Knee, subjects demonstrated statistically significant improvements in several aspects of gait though some were worsened while using the device. It is possible that these negative effects may be mitigated through longer term training and experience with the VI Knee. Given the demonstrated benefits and the potential to reduce or eliminate detriments through training, using a powered device like the VI Knee, particularly over an extended period of time, may help to improve walking performance and comfort.
Hahn, A.; Lang, M.; Stuckart, C.
In: Medicine, Bd. 95, Nr. 45, 2016, ISSN: 0025-7974.
@article{Hahn2016,
title = {Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings},
author = {A. Hahn and M. Lang and C. Stuckart},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613375887&from=export},
doi = {10.1097/md.0000000000005386},
issn = {0025-7974},
year = {2016},
date = {2016-01-01},
journal = {Medicine},
volume = {95},
number = {45},
address = {A. Hahn, Otto Bock Healthcare Products GmbH, Brehmstrasse 16, Vienna, Austria},
abstract = {The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.
2015
Dosen, S.; Markovic, M.; Somer, K.; Graimann, B.; Farina, D.
EMG Biofeedback for online predictive control of grasping force in a myoelectric prosthesis Artikel
In: J. NeuroEng. Rehabil., Bd. 12, Nr. 1, 2015, ISSN: 1743-0003.
@article{Dosen2015,
title = {EMG Biofeedback for online predictive control of grasping force in a myoelectric prosthesis},
author = {S. Dosen and M. Markovic and K. Somer and B. Graimann and D. Farina},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L605002250&from=export},
doi = {10.1186/s12984-015-0047-z},
issn = {1743-0003},
year = {2015},
date = {2015-06-01},
journal = {J. NeuroEng. Rehabil.},
volume = {12},
number = {1},
publisher = {Springer Science and Business Media LLC},
address = {D. Farina, Department of Neurorehabilitation Engineering, University Medical Center Göttingen (UMG), Georg-August University, Göttingen, Germany},
abstract = {Background: Active hand prostheses controlled using electromyography (EMG) signals have been used for decades to restore the grasping function, lost after an amputation. Although myocontrol is a simple and intuitive interface, it is also imprecise due to the stochastic nature of the EMG recorded using surface electrodes. Furthermore, the sensory feedback from the prosthesis to the user is still missing. In this study, we present a novel concept to close the loop in myoelectric prostheses. In addition to conveying the grasping force (system output), we provided to the user the online information about the system input (EMG biofeedback). Methods: As a proof-of-concept, the EMG biofeedback was transmitted in the current study using a visual interface (ideal condition). Ten able-bodied subjects and two amputees controlled a state-of-the-art myoelectric prosthesis in routine grasping and force steering tasks using EMG and force feedback (novel approach) and force feedback only (classic approach). The outcome measures were the variability of the generated forces and absolute deviation from the target levels in the routine grasping task, and the root mean square tracking error and the number of sudden drops in the force steering task. Results: During the routine grasping, the novel method when used by able-bodied subjects decreased twofold the force dispersion as well as absolute deviations from the target force levels, and also resulted in a more accurate and stable tracking of the reference force profiles during the force steering. Furthermore, the force variability during routine grasping did not increase for the higher target forces with EMG biofeedback. The trend was similar in the two amputees. Conclusions: The study demonstrated that the subjects, including the two experienced users of a myoelectric prosthesis, were able to exploit the online EMG biofeedback to observe and modulate the myoelectric signals, generating thereby more consistent commands. This allowed them to control the force predictively (routine grasping) and with a finer resolution (force steering). The future step will be to implement this promising and simple approach using an electrotactile interface. A prosthesis with a reliable response, following faithfully user intentions, would improve the utility during daily-life use and also facilitate the embodiment of the assistive system.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Active hand prostheses controlled using electromyography (EMG) signals have been used for decades to restore the grasping function, lost after an amputation. Although myocontrol is a simple and intuitive interface, it is also imprecise due to the stochastic nature of the EMG recorded using surface electrodes. Furthermore, the sensory feedback from the prosthesis to the user is still missing. In this study, we present a novel concept to close the loop in myoelectric prostheses. In addition to conveying the grasping force (system output), we provided to the user the online information about the system input (EMG biofeedback). Methods: As a proof-of-concept, the EMG biofeedback was transmitted in the current study using a visual interface (ideal condition). Ten able-bodied subjects and two amputees controlled a state-of-the-art myoelectric prosthesis in routine grasping and force steering tasks using EMG and force feedback (novel approach) and force feedback only (classic approach). The outcome measures were the variability of the generated forces and absolute deviation from the target levels in the routine grasping task, and the root mean square tracking error and the number of sudden drops in the force steering task. Results: During the routine grasping, the novel method when used by able-bodied subjects decreased twofold the force dispersion as well as absolute deviations from the target force levels, and also resulted in a more accurate and stable tracking of the reference force profiles during the force steering. Furthermore, the force variability during routine grasping did not increase for the higher target forces with EMG biofeedback. The trend was similar in the two amputees. Conclusions: The study demonstrated that the subjects, including the two experienced users of a myoelectric prosthesis, were able to exploit the online EMG biofeedback to observe and modulate the myoelectric signals, generating thereby more consistent commands. This allowed them to control the force predictively (routine grasping) and with a finer resolution (force steering). The future step will be to implement this promising and simple approach using an electrotactile interface. A prosthesis with a reliable response, following faithfully user intentions, would improve the utility during daily-life use and also facilitate the embodiment of the assistive system.
Hausmann, J.; Sweeney-Reed, C. M.; Sobieray, U.; Matzke, M.; Heinze, H. -J.; Voges, J.; Buentjen, L.
In: J. NeuroEng. Rehabil., Bd. 12, Nr. 1, 2015, ISSN: 1743-0003.
@article{Hausmann2015,
title = {Functional electrical stimulation through direct 4-channel nerve stimulation to improve gait in multiple sclerosis: a feasibility study},
author = {J. Hausmann and C. M. Sweeney-Reed and U. Sobieray and M. Matzke and H. -J. Heinze and J. Voges and L. Buentjen},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L606904897&from=export},
doi = {10.1186/s12984-015-0096-3},
issn = {1743-0003},
year = {2015},
date = {2015-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {12},
number = {1},
address = {J. Hausmann, Department of Neurology, Otto-von-Guericke University, Magdeburg, Leipziger Str. 44, Magdeburg, Germany},
abstract = {Background: Gait dysfunction due to lower limb central paralysis, frequently involving drop foot, is a common cause of disability in multiple sclerosis and has been treated with transcutaneous functional electrical stimulation (FES). We provide here the first report of 4-channel semi-implantable FES of the peroneal nerve which has been successfully used for rehabilitation in patients following stroke. Methods: FES was implemented via a 4-channel semi-implantable closed-loop system (ActiGait®, ©Ottobock), generating dorsiflexion in drop foot. Walking distance, gait symmetry (temporospatial gait analyses, Vicon Motion Systems®), gait velocity (10 m walking test) and quality of life (SF-36 questionnaire) were measured to evaluate the therapeutic benefit of this system in two patients with progressive MS. Results: Walking distance increased from 517 to 1884 m in Patient 1 and from 52 to 506 m in Patient 2. Gait velocity did not change significantly in Patient 1 and increased from 0.6 to 0.8 m/s in Patient 2. Maximum deviations of center of mass from the midline to each side changed significantly after 3 months of stimulation compared to baseline, decreasing from 15 to 12 mm in Patient 1 and from 47 to 37 mm in Patient 2. Both patients experienced reduced pain and fatigue and benefits to quality of life. Adverse events did not occur during the observation period. Conclusion: We conclude that implantable 4-channel FES systems are not only feasible but present a promising new alternative for treating central drop foot in MS patients.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Gait dysfunction due to lower limb central paralysis, frequently involving drop foot, is a common cause of disability in multiple sclerosis and has been treated with transcutaneous functional electrical stimulation (FES). We provide here the first report of 4-channel semi-implantable FES of the peroneal nerve which has been successfully used for rehabilitation in patients following stroke. Methods: FES was implemented via a 4-channel semi-implantable closed-loop system (ActiGait®, ©Ottobock), generating dorsiflexion in drop foot. Walking distance, gait symmetry (temporospatial gait analyses, Vicon Motion Systems®), gait velocity (10 m walking test) and quality of life (SF-36 questionnaire) were measured to evaluate the therapeutic benefit of this system in two patients with progressive MS. Results: Walking distance increased from 517 to 1884 m in Patient 1 and from 52 to 506 m in Patient 2. Gait velocity did not change significantly in Patient 1 and increased from 0.6 to 0.8 m/s in Patient 2. Maximum deviations of center of mass from the midline to each side changed significantly after 3 months of stimulation compared to baseline, decreasing from 15 to 12 mm in Patient 1 and from 47 to 37 mm in Patient 2. Both patients experienced reduced pain and fatigue and benefits to quality of life. Adverse events did not occur during the observation period. Conclusion: We conclude that implantable 4-channel FES systems are not only feasible but present a promising new alternative for treating central drop foot in MS patients.
2014
Whitehead, J. M. Aldridge; Wolf, E. J.; Scoville, C. R.; Wilken, J. M.
In: Clin. Orthop. Relat. Res., Bd. 472, Nr. 10, S. 3093–3101, 2014, ISSN: 0009-921X.
@article{AldridgeWhitehead2014,
title = {Does a Microprocessor-controlled Prosthetic Knee Affect Stair Ascent Strategies in Persons With Transfemoral Amputation?},
author = {J. M. Aldridge Whitehead and E. J. Wolf and C. R. Scoville and J. M. Wilken},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L608263443&from=export},
doi = {10.1007/s11999-014-3484-2},
issn = {0009-921X},
year = {2014},
date = {2014-10-01},
journal = {Clin. Orthop. Relat. Res.},
volume = {472},
number = {10},
pages = {3093–3101},
publisher = {Ovid Technologies (Wolters Kluwer Health)},
address = {J.M. Wilken, DOD-VA Extremity Trauma and Amputation Center of Excellence, Center for the Intrepid, Department of Orthopaedics and Rehabilitation, Brooke Army Medical Center, 3551 Roger Brooke Drive, Ft Sam Houston, TX, United States},
abstract = {Background: Stair ascent can be difficult for individuals with transfemoral amputation because of the loss of knee function. Most individuals with transfemoral amputation use either a step-to-step (nonreciprocal, advancing one stair at a time) or skip-step strategy (nonreciprocal, advancing two stairs at a time), rather than a step-over-step (reciprocal) strategy, because step-to-step and skip-step allow the leading intact limb to do the majority of work. A new microprocessor-controlled knee (Ottobock X2®) uses flexion/extension resistance to allow step-over-step stair ascent. Questions/Purposes: We compared self-selected stair ascent strategies between conventional and X2® prosthetic knees, examined between-limb differences, and differentiated stair ascent mechanics between X2® users and individuals without amputation. We also determined which factors are associated with differences in knee position during initial contact and swing within X2® users. Methods: Fourteen individuals with transfemoral amputation participated in stair ascent sessions while using conventional and X2® knees. Ten individuals without amputation also completed a stair ascent session. Lower-extremity stair ascent joint angles, moment, and powers and ground reaction forces were calculated using inverse dynamics during self-selected strategy and cadence and controlled cadence using a step-over-step strategy. Results: One individual with amputation self-selected a step-over-step strategy while using a conventional knee, while 10 individuals self-selected a step-over-step strategy while using X2® knees. Individuals with amputation used greater prosthetic knee flexion during initial contact (32.5°},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Stair ascent can be difficult for individuals with transfemoral amputation because of the loss of knee function. Most individuals with transfemoral amputation use either a step-to-step (nonreciprocal, advancing one stair at a time) or skip-step strategy (nonreciprocal, advancing two stairs at a time), rather than a step-over-step (reciprocal) strategy, because step-to-step and skip-step allow the leading intact limb to do the majority of work. A new microprocessor-controlled knee (Ottobock X2®) uses flexion/extension resistance to allow step-over-step stair ascent. Questions/Purposes: We compared self-selected stair ascent strategies between conventional and X2® prosthetic knees, examined between-limb differences, and differentiated stair ascent mechanics between X2® users and individuals without amputation. We also determined which factors are associated with differences in knee position during initial contact and swing within X2® users. Methods: Fourteen individuals with transfemoral amputation participated in stair ascent sessions while using conventional and X2® knees. Ten individuals without amputation also completed a stair ascent session. Lower-extremity stair ascent joint angles, moment, and powers and ground reaction forces were calculated using inverse dynamics during self-selected strategy and cadence and controlled cadence using a step-over-step strategy. Results: One individual with amputation self-selected a step-over-step strategy while using a conventional knee, while 10 individuals self-selected a step-over-step strategy while using X2® knees. Individuals with amputation used greater prosthetic knee flexion during initial contact (32.5°
Kistenberg, R. S.
Prosthetic choices for people with leg and arm amputations Artikel
In: Phys. Med. Rehabil. Clin. North Am., Bd. 25, Nr. 1, S. 93–115, 2014, ISSN: 1558-1381.
@article{Kistenberg2014,
title = {Prosthetic choices for people with leg and arm amputations},
author = {R. S. Kistenberg},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L370343297&from=export},
doi = {10.1016/j.pmr.2013.10.001},
issn = {1558-1381},
year = {2014},
date = {2014-01-01},
journal = {Phys. Med. Rehabil. Clin. North Am.},
volume = {25},
number = {1},
pages = {93–115},
address = {R.S. Kistenberg, Georgia Institute of Technology, School of Applied Physiology, 555 14th Street, Atlanta, GA 30318, United States},
abstract = {New technology and materials have advanced prosthetic designs to enable people who rely on artificial limbs to achieve feats never dreamed before. However, the latest and the greatest technology is not appropriate for everyone. The aim of this article is to present contemporary options that are available for people who rely on artificial limbs to enhance their quality of life for mobility and independence. © 2014 Elsevier Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
New technology and materials have advanced prosthetic designs to enable people who rely on artificial limbs to achieve feats never dreamed before. However, the latest and the greatest technology is not appropriate for everyone. The aim of this article is to present contemporary options that are available for people who rely on artificial limbs to enhance their quality of life for mobility and independence. © 2014 Elsevier Inc.
Chitragari, G.; Mahler, D. B.; Sumpio, B. J.; Blume, P. A.; Sumpio, B. E.
Prosthetic options available for the diabetic lower limb amputee Artikel
In: Clin. Podiatr. Med. Surg., Bd. 31, Nr. 1, S. 174–185, 2014, ISSN: 1558-2302.
@article{Chitragari2014,
title = {Prosthetic options available for the diabetic lower limb amputee},
author = {G. Chitragari and D. B. Mahler and B. J. Sumpio and P. A. Blume and B. E. Sumpio},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L370343216&from=export},
doi = {10.1016/j.cpm.2013.09.008},
issn = {1558-2302},
year = {2014},
date = {2014-01-01},
journal = {Clin. Podiatr. Med. Surg.},
volume = {31},
number = {1},
pages = {174–185},
address = {B.E. Sumpio, Yale University School of Medicine, 333 Cedar Street, BB 204, New Haven, CT 06520-8062, United States},
abstract = {Although the rate of lower limb amputation in patients with diabetes is decreasing, amputation still remains a major complication of diabetes. Prosthetics have been long used to help amputees ambulate. The last decade has seen many advances in prostheses with the enhanced understanding of the mechanics of ambulation and improved use of technology. This review describes the different types of prosthetic options available for below knee, ankle, and foot amputees, emphasizing the latest advances in prosthetic design. © 2014 Elsevier Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Although the rate of lower limb amputation in patients with diabetes is decreasing, amputation still remains a major complication of diabetes. Prosthetics have been long used to help amputees ambulate. The last decade has seen many advances in prostheses with the enhanced understanding of the mechanics of ambulation and improved use of technology. This review describes the different types of prosthetic options available for below knee, ankle, and foot amputees, emphasizing the latest advances in prosthetic design. © 2014 Elsevier Inc.
2013
Komolafe, O.; Wood, S.; Caldwell, R.; Hansen, A.; Fatone, S.
Methods for characterization of mechanical and electrical prosthetic vacuum pumps Artikel
In: J. Rehabil. Res. Dev., Bd. 50, Nr. 8, S. 1069–1078, 2013, ISSN: 1938-1352.
@article{Komolafe2013,
title = {Methods for characterization of mechanical and electrical prosthetic vacuum pumps},
author = {O. Komolafe and S. Wood and R. Caldwell and A. Hansen and S. Fatone},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L370540897&from=export},
doi = {10.1682/jrrd.2012.11.0204},
issn = {1938-1352},
year = {2013},
date = {2013-01-01},
journal = {J. Rehabil. Res. Dev.},
volume = {50},
number = {8},
pages = {1069–1078},
address = {S. Fatone, Northwestern University, Prosthetics-Orthotics Center, 680 N Lake Shore Dr, Suite 1100, Chicago, IL 60611, United States},
abstract = {Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.
Fligge, N.; Urbanek, H.; der Smagt, P. Van
Relation between object properties and EMG during reaching to grasp Artikel
In: J. Electromyogr. Kinesiology, Bd. 23, Nr. 2, S. 402–410, 2013, ISSN: 1873-5711.
@article{Fligge2013,
title = {Relation between object properties and EMG during reaching to grasp},
author = {N. Fligge and H. Urbanek and P. Van der Smagt},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L52331059&from=export},
doi = {10.1016/j.jelekin.2012.10.010},
issn = {1873-5711},
year = {2013},
date = {2013-01-01},
journal = {J. Electromyogr. Kinesiology},
volume = {23},
number = {2},
pages = {402–410},
address = {N. Fligge, German Aerospace Center (DLR), Center for Robotics and Mechatronics, Muenchner Strasse 20, D-82234 Oberpfaffenhofen-Wessling, Germany},
abstract = {In order to stably grasp an object with an artificial hand, a priori knowledge of the object's properties is a major advantage, especially to ensure subsequent manipulation of the object held by the hand. This is also true for hand prostheses: pre-shaping of the hand while approaching the object, similar to able-bodied, allows the wearer for a much faster and more intuitive way of handling and grasping an object. For hand prostheses, it would be advantageous to obtain this information about object properties from a surface electromyography (sEMG) signal, which is already present and used to control the active prosthetic hand.We describe experiments in which human subjects grasp different objects at different positions while their muscular activity is recorded through eight sEMG electrodes placed on the forearm. Results show that sEMG data, gathered before the hand is in contact with the object, can be used to obtain relevant information on object properties such as size and weight. © 2012 Elsevier Ltd.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In order to stably grasp an object with an artificial hand, a priori knowledge of the object's properties is a major advantage, especially to ensure subsequent manipulation of the object held by the hand. This is also true for hand prostheses: pre-shaping of the hand while approaching the object, similar to able-bodied, allows the wearer for a much faster and more intuitive way of handling and grasping an object. For hand prostheses, it would be advantageous to obtain this information about object properties from a surface electromyography (sEMG) signal, which is already present and used to control the active prosthetic hand.We describe experiments in which human subjects grasp different objects at different positions while their muscular activity is recorded through eight sEMG electrodes placed on the forearm. Results show that sEMG data, gathered before the hand is in contact with the object, can be used to obtain relevant information on object properties such as size and weight. © 2012 Elsevier Ltd.
2012
Portnoy, S.; Kristal, A.; Gefen, A.; Siev-Ner, I.
In: Gait Posture, Bd. 35, Nr. 1, S. 121–125, 2012, ISSN: 1879-2219.
@article{Portnoy2012,
title = {Outdoor dynamic subject-specific evaluation of internal stresses in the residual limb: Hydraulic energy-stored prosthetic foot compared to conventional energy-stored prosthetic feet},
author = {S. Portnoy and A. Kristal and A. Gefen and I. Siev-Ner},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L51635905&from=export},
doi = {10.1016/j.gaitpost.2011.08.021},
issn = {1879-2219},
year = {2012},
date = {2012-01-01},
journal = {Gait Posture},
volume = {35},
number = {1},
pages = {121–125},
address = {S. Portnoy, Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel},
abstract = {The prosthetic foot plays an important role in propelling, breaking, balancing and supporting body loads while the amputee ambulates on different grounds. It is therefore important to quantify the effect of the prosthetic foot mechanism on biomechanical parameters, in order to prevent pressure ulcers and deep tissue injury. Our aim was to monitor the internal stresses in the residuum of transtibial amputation (TTA) prosthetic-users ambulating on different terrains, which the amputees encounter during their daily activities, i.e. paved floor, grass, ascending and descending stairs and slope. We specifically aimed to compare between the internal stresses in the TTA residuum of amputees ambulating with a novel hydraulic prosthetic foot compared to conventional energy storage and return (ESR) prosthetic feet. Monitoring of internal stresses was accomplished using a portable subject-specific real-time internal stress monitor. We found significant decrease (p<. 0.01) in peak internal stresses and in the loading rate of the amputated limb, while walking with the hydraulic foot, compared to walking with ESR feet. The loading rate calculated while ambulating with the hydraulic foot was at least three times lower than the loading rate calculated while ambulating with the ESR foot. Although the average decrease in internal stresses was ∼2-fold larger when replacing single-toe ESR feet with the hydraulic foot than when replacing split-toed ESR feet with the hydraulic foot, the differences were statistically insignificant. Our findings suggest that using a hydraulic prosthetic foot may protect the distal tibial end of the TTA residuum from high stresses, therefore preventing pressure-related injury and pain. © 2011 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The prosthetic foot plays an important role in propelling, breaking, balancing and supporting body loads while the amputee ambulates on different grounds. It is therefore important to quantify the effect of the prosthetic foot mechanism on biomechanical parameters, in order to prevent pressure ulcers and deep tissue injury. Our aim was to monitor the internal stresses in the residuum of transtibial amputation (TTA) prosthetic-users ambulating on different terrains, which the amputees encounter during their daily activities, i.e. paved floor, grass, ascending and descending stairs and slope. We specifically aimed to compare between the internal stresses in the TTA residuum of amputees ambulating with a novel hydraulic prosthetic foot compared to conventional energy storage and return (ESR) prosthetic feet. Monitoring of internal stresses was accomplished using a portable subject-specific real-time internal stress monitor. We found significant decrease (p<. 0.01) in peak internal stresses and in the loading rate of the amputated limb, while walking with the hydraulic foot, compared to walking with ESR feet. The loading rate calculated while ambulating with the hydraulic foot was at least three times lower than the loading rate calculated while ambulating with the ESR foot. Although the average decrease in internal stresses was ∼2-fold larger when replacing single-toe ESR feet with the hydraulic foot than when replacing split-toed ESR feet with the hydraulic foot, the differences were statistically insignificant. Our findings suggest that using a hydraulic prosthetic foot may protect the distal tibial end of the TTA residuum from high stresses, therefore preventing pressure-related injury and pain. © 2011 Elsevier B.V.
2010
Ludwigs, E.; Bellmann, M.; Schmalz, T.; Blumentritt, S.
Biomechanical differences between two exoprosthetic hip joint systems during level walking Artikel
In: Prosthet. Orthot. Int., Bd. 34, Nr. 4, S. 449–460, 2010, ISSN: 1746-1553.
@article{Ludwigs2010,
title = {Biomechanical differences between two exoprosthetic hip joint systems during level walking},
author = {E. Ludwigs and M. Bellmann and T. Schmalz and S. Blumentritt},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L360015209&from=export},
doi = {10.3109/03093646.2010.499551},
issn = {1746-1553},
year = {2010},
date = {2010-01-01},
journal = {Prosthet. Orthot. Int.},
volume = {34},
number = {4},
pages = {449–460},
address = {E. Ludwigs, Research Department, Otto Bock HealthCare GmbH, Hermann-Rein-Str. 2a, Gttingen, 37075, Germany},
abstract = {Previous studies have shown low end-user acceptance of a hip disarticulation style prosthesis and that the limitations of such prostheses, including poor gait pattern, socket discomfort, weight of the prosthesis, loss of mobility, instability and high energy consumption are a contributing factor. This study was initiated to determine if a new style of prosthetic hip joint could help to overcome some of the limitations concerning the gait pattern. The present study analyzed the gait pattern of six hip disarticulation amputee subjects. The objective was to compare two different prosthetic hip joints, both from Otto Bock HealthCare: The new Helix3D and the 7E7, which is based on the Canadian model proposed by McLaurin (1954). Kinematics and kinetics were recorded by an optoelectronic camera system with six CCD cameras and two force plates. During weight acceptance, the Helix3D extends considerably slower and reaches full extension later than the 7E7. The increased range of pelvic tilt observed with hip disarticulation amputees is significantly reduced (by 5±3 degrees) when using the Helix3D Hip Joint. In addition, this system showed increased stance phase knee joint flexion as well as increased maximum swing phase knee flexion angles compared to the 7E7. These motion analysis results show that the Helix3D Hip Joint can reduce gait abnormalities compared to the uniplanar design of the 7E7 hip joint. © 2010 ISPO.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Previous studies have shown low end-user acceptance of a hip disarticulation style prosthesis and that the limitations of such prostheses, including poor gait pattern, socket discomfort, weight of the prosthesis, loss of mobility, instability and high energy consumption are a contributing factor. This study was initiated to determine if a new style of prosthetic hip joint could help to overcome some of the limitations concerning the gait pattern. The present study analyzed the gait pattern of six hip disarticulation amputee subjects. The objective was to compare two different prosthetic hip joints, both from Otto Bock HealthCare: The new Helix3D and the 7E7, which is based on the Canadian model proposed by McLaurin (1954). Kinematics and kinetics were recorded by an optoelectronic camera system with six CCD cameras and two force plates. During weight acceptance, the Helix3D extends considerably slower and reaches full extension later than the 7E7. The increased range of pelvic tilt observed with hip disarticulation amputees is significantly reduced (by 5±3 degrees) when using the Helix3D Hip Joint. In addition, this system showed increased stance phase knee joint flexion as well as increased maximum swing phase knee flexion angles compared to the 7E7. These motion analysis results show that the Helix3D Hip Joint can reduce gait abnormalities compared to the uniplanar design of the 7E7 hip joint. © 2010 ISPO.
2004
Wit, D. C. M.; Buurke, J. H.; Nijlant, J. M. M.; IJzerman, M. J.; Hermens, H. J.
In: Clin. Rehabil., Bd. 18, Nr. 5, S. 550–557, 2004, ISSN: 0269-2155.
@article{Wit2004,
title = {The effect of an ankle-foot orthosis on walking ability in chronic stroke patients: A randomized controlled trial},
author = {D. C. M. Wit and J. H. Buurke and J. M. M. Nijlant and M. J. IJzerman and H. J. Hermens},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L39076880&from=export},
doi = {10.1191/0269215504cr770oa},
issn = {0269-2155},
year = {2004},
date = {2004-01-01},
journal = {Clin. Rehabil.},
volume = {18},
number = {5},
pages = {550–557},
address = {D.C.M. de Wit, Roessingh Research and Development, Roessinghbleekweg 33B, 7522 AH Enschede, Netherlands},
abstract = {Objective: Regaining walking ability is a major goal during the rehabilitation of stroke patients. To support this process an ankle-foot orthosis (AFC) is often prescribed. The aim of this study is to investigate the effect of an AFO on walking ability in chronic stroke patients. Design: Cross-over design with randomization for the interventions. Methods: Twenty chronic stroke patients, wearing an AFO for at least six months, were included. Walking ability was operationalized as comfortable walking speed, scores on the timed up and go (TUG) test and stairs test. Patients were measured with and without their AFO, the sequence of which was randomized. Additionally, subjective impressions of self-confidence and difficulty of the tasks were scored. Clinically relevant differences based on literature were defined for walking speed (20 cm/s), the TUG test (10 s). Gathered data were statistically analysed using a paired t-test. Results: The mean difference in favour of the AFO in walking speed was 4.8 cm/s (95% CI 0.85-8.7), in the TUG test 3.6 s (95% CI 2.4-4.8) and in the stairs test 8.6 s (95% CI 3.1-14.1). Sixty-five per cent of the patients experienced less difficulty and 70% of the patients felt more self-confident while wearing the AFO. Conclusions: The effect of an AFO on walking ability is statistically significant, but compared with the a priori defined differences it is too small to be clinically relevant. The effect on self-confidence suggests that other factors might play an important role in the motivation to use an AFO. © Arnold 2004.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objective: Regaining walking ability is a major goal during the rehabilitation of stroke patients. To support this process an ankle-foot orthosis (AFC) is often prescribed. The aim of this study is to investigate the effect of an AFO on walking ability in chronic stroke patients. Design: Cross-over design with randomization for the interventions. Methods: Twenty chronic stroke patients, wearing an AFO for at least six months, were included. Walking ability was operationalized as comfortable walking speed, scores on the timed up and go (TUG) test and stairs test. Patients were measured with and without their AFO, the sequence of which was randomized. Additionally, subjective impressions of self-confidence and difficulty of the tasks were scored. Clinically relevant differences based on literature were defined for walking speed (20 cm/s), the TUG test (10 s). Gathered data were statistically analysed using a paired t-test. Results: The mean difference in favour of the AFO in walking speed was 4.8 cm/s (95% CI 0.85-8.7), in the TUG test 3.6 s (95% CI 2.4-4.8) and in the stairs test 8.6 s (95% CI 3.1-14.1). Sixty-five per cent of the patients experienced less difficulty and 70% of the patients felt more self-confident while wearing the AFO. Conclusions: The effect of an AFO on walking ability is statistically significant, but compared with the a priori defined differences it is too small to be clinically relevant. The effect on self-confidence suggests that other factors might play an important role in the motivation to use an AFO. © Arnold 2004.