Persons with Unilateral Transtibial Amputations Modulate Ipsilateral Hip and Contralateral Ankle Joint Work to Accelerate and Decelerate Walking

Abstract

ABSTRACT Introduction Loss of power production at the ankle joint contributes to many problems people with unilateral transtibial (UTT) amputation experience during walking. Little is known about walking acceleration and deceleration, which is common in daily living and may require substantial compensatory behaviors from the residual lower-limb joints. Objective The aim of this study was to quantify individual lower-limb joint contributions to walking acceleration and deceleration in people with UTT amputations. We hypothesized that joint work on the prosthetic limb would be primarily modulated at the hip, and joint work on the sound limb would be primarily modulated at the ankle. Study Design The study is a repeated-measures design. Methods Six K3 level ambulators with UTT amputations participated. Participants performed a total of 40 walking trials while wearing their own nonarticulated dynamic prosthetic foot and socket. Each trial consisted of walking along a straight walkway. After walking approximately 2 m, participants received a cue instructing them to perform one of three walking conditions: continue walking at a constant average velocity, rapidly accelerate, or rapidly decelerate. We used ground reaction forces and motion capture data to derive joint kinematics and kinetics during the three walking conditions. We used one-way repeated-measures analyses of variance (ANOVAs) to identify significant differences between conditions. Results For the sound limb, positive hip and ankle work was significantly greater during acceleration compared with constant average velocity or deceleration conditions, and negative knee work was significantly greater during acceleration compared with deceleration. For the prosthetic limb, negative ankle work was significantly greater during acceleration compared with deceleration. Conclusions People with UTT amputation who use nonarticulated prostheses primarily modulated joint work on their sound limb to accelerate or decelerate walking speed. Clinical Relevance Characterizing compensatory behaviors of people with a UTT amputation is important for understanding injury mechanisms, informing clinical guidelines, and improving future ankle-foot prosthesis designs.