Transtibial amputee gait efficiency : energy storage and return versus solid ankle cushioned heel prosthetic feet

Abstract

Energy storage and return (ESR) feet have long been assumed to promote metabolically efficient amputee gait. However, despite being prescribed for approximately thirty years, there is limited evidence that they achieve this desired function. Here, we report a meta-analysis of data from ten studies which met our selection criteria to determine whether amputee walking with ESR feet is more efficient than with conventional solid ankle cushioned heel (SACH) feet. Additionally, the data were tested for a relationship with walking speed; since it has been suggested ESR feet might perform better at higher speeds. The raw data are highly variable due to differences in study protocols; therefore we normalised the data and found a statistically significant difference (p < 0.001) between ESR and SACH feet. However, the magnitude of this difference is small, with the cost of transport (COT) with ESR feet being 97.3% of the cost with SACH feet. No relationship between ESR COT and speed was found (p = 0.191). In the authors’ opinion, these results suggest that ESR feet are not effective at improving amputee COT to a clinically relevant degree. We hypothesise this is due to limited push-off at the end of stance compared with able-bodied ankles