TPress
1.
Ernst, M.; Altenburg, B.; Bellmann, M.; Schmalz, T.
In: J. NeuroEng. Rehabil., Bd. 14, Nr. 1, 2017, ISSN: 1743-0003.
Abstract | Links | Schlagwörter: adult, article, autoadaptive dorsiflexion stop, controlled study, foot prosthesis, Genium, ground reaction force, human, human experiment, informed consent, joint angle, joint torque, leg amputation, male, microprocessor, microprocessor controlled prosthetic feet, musculoskeletal function, musculoskeletal system parameters, priority journal, standing, task performance, transfemoral amputation, transtibial amputation, vertical ground reaction force
@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 = {adult, article, autoadaptive dorsiflexion stop, controlled study, foot prosthesis, Genium, ground reaction force, human, human experiment, informed consent, joint angle, joint torque, leg amputation, male, microprocessor, microprocessor controlled prosthetic feet, musculoskeletal function, musculoskeletal system parameters, priority journal, standing, task performance, transfemoral amputation, transtibial amputation, vertical ground reaction force},
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.
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.
2017
Ernst, M.; Altenburg, B.; Bellmann, M.; Schmalz, T.
In: J. NeuroEng. Rehabil., Bd. 14, Nr. 1, 2017, ISSN: 1743-0003.
Abstract | Links | Schlagwörter: adult, article, autoadaptive dorsiflexion stop, controlled study, foot prosthesis, Genium, ground reaction force, human, human experiment, informed consent, joint angle, joint torque, leg amputation, male, microprocessor, microprocessor controlled prosthetic feet, musculoskeletal function, musculoskeletal system parameters, priority journal, standing, task performance, transfemoral amputation, transtibial amputation, vertical ground reaction force
@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 = {adult, article, autoadaptive dorsiflexion stop, controlled study, foot prosthesis, Genium, ground reaction force, human, human experiment, informed consent, joint angle, joint torque, leg amputation, male, microprocessor, microprocessor controlled prosthetic feet, musculoskeletal function, musculoskeletal system parameters, priority journal, standing, task performance, transfemoral amputation, transtibial amputation, vertical ground reaction force},
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.
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.
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.
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.