TPress
1.
Köhler, T. M.; Blumentritt, S.; Braatz, F.; Bellmann, M.
In: Gait Posture, Bd. 89, S. 169–177, 2021, ISSN: 0966-6362.
Abstract | Links | Schlagwörter: above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed
@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 = {above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed},
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.
2.
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.
Abstract | Links | Schlagwörter: above knee amputation, adult, aged, article, biomechanics, body position, C-leg, clinical article, College Park Trustep, controlled study, female, foot prosthesis, gait, gait biomechanics, hip, hip extension moment, human, knee power, knee prosthesis, Low Profile Vari-Flex, male, musculoskeletal system parameters, priority journal, range of motion, robotic variable impedance prosthetic knee, step length symmetry, torso lean angle, Triton, VI Knee, walking speed
@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 = {above knee amputation, adult, aged, article, biomechanics, body position, C-leg, clinical article, College Park Trustep, controlled study, female, foot prosthesis, gait, gait biomechanics, hip, hip extension moment, human, knee power, knee prosthesis, Low Profile Vari-Flex, male, musculoskeletal system parameters, priority journal, range of motion, robotic variable impedance prosthetic knee, step length symmetry, torso lean angle, Triton, VI Knee, walking speed},
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.
2021
Köhler, T. M.; Blumentritt, S.; Braatz, F.; Bellmann, M.
In: Gait Posture, Bd. 89, S. 169–177, 2021, ISSN: 0966-6362.
Abstract | Links | Schlagwörter: above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed
@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 = {above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed},
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.
2016
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.
Abstract | Links | Schlagwörter: above knee amputation, adult, aged, article, biomechanics, body position, C-leg, clinical article, College Park Trustep, controlled study, female, foot prosthesis, gait, gait biomechanics, hip, hip extension moment, human, knee power, knee prosthesis, Low Profile Vari-Flex, male, musculoskeletal system parameters, priority journal, range of motion, robotic variable impedance prosthetic knee, step length symmetry, torso lean angle, Triton, VI Knee, walking speed
@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 = {above knee amputation, adult, aged, article, biomechanics, body position, C-leg, clinical article, College Park Trustep, controlled study, female, foot prosthesis, gait, gait biomechanics, hip, hip extension moment, human, knee power, knee prosthesis, Low Profile Vari-Flex, male, musculoskeletal system parameters, priority journal, range of motion, robotic variable impedance prosthetic knee, step length symmetry, torso lean angle, Triton, VI Knee, walking speed},
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.
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.
2016
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.