Changes in activities-specific balance confidence of active unilateral transtibial prosthesis users after provision of a self-aligning ankle foot

Abstract

Background: Self-aligning ankle feet have an increased range of motion and are marketed to improve compliance over uneven terrain and increase function and balance; however, much of the existing literature focuses on the biomechanical aspect of these prostheses as opposed to patient-reported measures. Objective: To compare activities-specific balance confidence (ABC), health-related quality of life (HR-QoL), perceived mobility, gait speed, and step length before and after provision of a self-aligning ankle foot in the active unilateral transtibial prosthesis user. Study Design: Retrospective analysis of prospectively collected data. Methods: Patient-reported and functional measures were captured for 85 users who were provided with a self-aligning ankle foot. Measures were recorded immediately before self-aligning ankle foot provision and again at 6 months afterward. The primary outcome was the ABC Score, along with the following secondary measures; HR-QoL using EQ-5D-5L Health Index Prosthetic Limb User Survey of Mobility and 10-meter timed walk test. Results: The median age of the cohort was 55.2 years old and 71% were males, with the majority having their transtibial amputation due to trauma. There was a statistically significant improvement in ABC from 76 to 86% (p < 0.001) with a medium effect size. There was no statistically significant improvement in HR-QoL (p = 0.051), Prosthetic Limb User Survey of Mobility (p = 0.043), time taken to walk 10 m (p = 0.15) and step length (p = 0.003). Conclusions: Self aligning ankle feet increased ABC and step length with no detrimental effect on HR-QoL, perceived mobility or walking speed in those with a unilateral trans-tibial amputation.