TY - JOUR
T1 - The biomechanical response of persons with transfemoral amputation to variations in prosthetic knee alignment during level walking
AU - Koehler-McNicholas, Sara R.
AU - Lipschutz, Robert D.
AU - Gard, Steven A.
N1 - Funding Information:
This material was based on work supported by the VA, Office of Research and Development, Rehabilitation Research and Development Service (award VA RR&D RX000143) and was administered by the Jesse Brown VA Medical Center, Chicago, Illinois. This research was also partially funded by the Orthotics and Prosthetics Education and Research Foundation (grant OPERF-2009-FA-12) and the National Institute on Disability and Rehabilitation Research (NIDRR) of the U.S. Department of Education (grant H133E080009; Principal Investigators: Steven Gard and Stefania Fatone).
Publisher Copyright:
© 2016, Rehabilitation Research and Development Service. All rights reserved.
PY - 2016
Y1 - 2016
N2 - Prosthetic alignment is an important factor in the overall fit and performance of a lower-limb prosthesis. However, the association between prosthetic alignment and control strategies used by persons with transfemoral amputation to coordinate the movement of a passive prosthetic knee is poorly understood. This study investigated the biomechanical response of persons with transfemoral amputation to systematic perturbations in knee joint alignment during a level walking task. Quantitative gait data were collected for three alignment conditions: bench alignment, 2 cm anterior knee translation (ANT), and 2 cm posterior knee translation (POST). In response to a destabilizing alignment perturbation (i.e., the ANT condition), participants significantly increased their early-stance hip extension moment, confirming that persons with transfemoral amputation rely on a hip extensor strategy to maintain knee joint stability. However, participants also decreased the rate at which they loaded their prosthesis, decreased their affected-side step length, increased their trunk flexion, and maintained their prosthesis in a more vertical posture at the time of opposite toe off. Collectively, these results suggest that persons with transfemoral amputation rely on a combination of strategies to coordinate stance-phase knee flexion. Further, comparatively few significant changes were observed in response to the POST condition, suggesting that a bias toward posterior alignment may have fewer implications in terms of stance-phase, knee joint control.
AB - Prosthetic alignment is an important factor in the overall fit and performance of a lower-limb prosthesis. However, the association between prosthetic alignment and control strategies used by persons with transfemoral amputation to coordinate the movement of a passive prosthetic knee is poorly understood. This study investigated the biomechanical response of persons with transfemoral amputation to systematic perturbations in knee joint alignment during a level walking task. Quantitative gait data were collected for three alignment conditions: bench alignment, 2 cm anterior knee translation (ANT), and 2 cm posterior knee translation (POST). In response to a destabilizing alignment perturbation (i.e., the ANT condition), participants significantly increased their early-stance hip extension moment, confirming that persons with transfemoral amputation rely on a hip extensor strategy to maintain knee joint stability. However, participants also decreased the rate at which they loaded their prosthesis, decreased their affected-side step length, increased their trunk flexion, and maintained their prosthesis in a more vertical posture at the time of opposite toe off. Collectively, these results suggest that persons with transfemoral amputation rely on a combination of strategies to coordinate stance-phase knee flexion. Further, comparatively few significant changes were observed in response to the POST condition, suggesting that a bias toward posterior alignment may have fewer implications in terms of stance-phase, knee joint control.
KW - Alignment
KW - Amputation
KW - Artificial limbs
KW - Gait analysis
KW - Hip
KW - Knee
KW - Load cell
KW - Transfemoral
KW - Treadmill
KW - Trunk
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U2 - 10.1682/JRRD.2014.12.0311
DO - 10.1682/JRRD.2014.12.0311
M3 - Article
C2 - 28355034
AN - SCOPUS:85016157973
SN - 0748-7711
VL - 53
SP - 1089
EP - 1106
JO - Journal of Rehabilitation Research and Development
JF - Journal of Rehabilitation Research and Development
IS - 6
ER -