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

Energy storage and return (ESR) feet have long been assumed to promote metabolically efficient amputee gait. However, despite being prescribed for approximately 30 yr, there is limited evidence that they achieve this desired function. Here, we report a meta-analysis of data from 10 studies that 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 because of differences in study protocols; therefore, we normalized 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 = 0.19). We hypothesize that the small but statistically significant difference between ESR and SACH feet may not constitute a functionally significant improvement in COT, possibly related to the limited push-off power provided by ESR feed compared with nondisabled ankles.