Effects of high-profile crossover feet on gait biomechanics in 2 individuals with Syme amputation.

Abstract

Prosthetic treatment options for people with ankle disarticulation (i.e., Syme amputation) are limited. Prosthetic feet designed for people with Syme amputation are often low profile to accommodate build-height restrictions, resulting in decreased energy return during gait. High-profile crossover feet that attach to the posterior proximal aspect of the prosthetic socket can bypass these restrictions and may promote a more physiologic gait pattern. To compare level-ground gait biomechanics and patient-reported outcomes between crossover and traditional energy-storing feet in people with Syme amputation. Within-participant pilot study. Both participants were fit with energy-storing and crossover feet and were randomized to the order they used the feet. Participants used each foot for 2 weeks before assessment. Step length symmetry, prosthetic ankle range of motion, prosthetic-side energy return, and peak sound-side loading were determined from motion capture data obtained in a laboratory. Mobility and balance confidence were measured using standardized patient-reported outcome measures. Foot preference was assessed with an ad hoc survey. Two participants with Syme amputations completed the study. Prosthetic ankle peak dorsiflexion and push-off power increased with the crossover foot compared with the energy-storing foot for both participants. Both participants reported an overall preference of the crossover foot. Changes in patient-reported outcomes did not exceed published minimum detectable change values. Crossover feet increased prosthetic ankle range of motion and energy return compared with traditional energy-storing feet in this pilot investigation of 2 participants. Crossover feet seem to promote physiologic gait and may be a promising alternative to traditional low-profile feet for people with Syme amputation.