Background: Prosthetic alignment is usually unchanged once optimized. However, a previous study indicated that long-distance walking significantly altered gait patterns, suggesting some alignment adjustments after walking are required. This study investigated the effects of alignment changes (by inserting a heel lift) on gait of a transtibial amputee before and after treadmill walking.
Case description and methods: The subject walked, without heel lifts, on a treadmill until perception of fatigue. Gait changes upon heel lifting at the prosthetic side were studied before and after the treadmill walking
Findings and outcomes: For this subject before the treadmill walking, heel lifting induced drop-off with increased prosthetic-side knee flexion at mid-stance and pre-swing. The sound limb outreached to stabilize the gait. After the treadmill walking, the same heel lift did not induce drop-off. It reduced the plantar flexor power generation, potentially delaying its fatigue.
Conclusion: After walking prosthetic-side heel lifting could be beneficial.
Clinical relevance: Many lower-limb amputees have difficulties in long-distance walking due to muscle fatigue. This case study proposes that appropriate alignment changes after some walking potentially relieve fatigue and encourage them to walk longer distances.
Keywords: Gait; heel lift; long-distance walking; muscle fatigue; prosthetic alignment; transtibial amputees.