Article

OBJECTIVE: To investigate which strategies transtibial amputees use to cope with
challenges of gait stability and gait adaptability, and how these strategies
differ from strategies used by able-bodied controls. DESIGN: Cross-sectional
study. SETTING: An instrumented treadmill mounted onto a 6 degrees -of-freedom
motion platform in combination with a virtual environment. PARTICIPANTS:
Transtibial amputees (n=10) and able-bodied controls (n=9). INTERVENTIONS:
Mediolateral (ML) translations of the walking surface were imposed to manipulate
gait stability. To provoke an adaptive gait pattern, a gait adaptability task was
used in which subjects had to hit virtual targets with markers guided by their
knees. MAIN OUTCOME MEASURES: Walking speed, step length, step frequency, step
width, and selected measures of gait stability (short-term Lyapunov exponents and
backward and ML margins of stability [MoS]). RESULTS: Amputees walked slower than
able-bodied people, with a lower step frequency and wider steps. This resulted in
a larger ML MoS but a smaller backward MoS for amputees. In response to the
balance perturbation, both groups decreased step length and increased step
frequency and step width. Walking speed did not change significantly in response
to the perturbation. These adaptations induced an increase in ML and backward
MoS. To perform the gait adaptability task, both groups decreased step length and
increased step width, but did not change step frequency and walking speed. ML and
backward MoS were maintained in both groups. CONCLUSIONS: Transtibial amputees
have the capacity to use the same strategies to deal with challenges of gait
stability and adaptability, to the same extent as able-bodied people.
CI - Copyright (c) 2013 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS