Functional impact of a new prosthetic foot design in transtibial amputation, a comparative study

Abstract

Prosthetic feet designs are complex with energy storage and shock absorption characteristics. These feet store energy in the heel and the mid-foot during loading and release energy at push off. Device selection is based on subjective criteria because of a lack of quantitative methods. Studies have compared different prosthetic feet however, did not include functional outcome and rating for comfort. This study evaluated a new prosthetic foot (Pro-Flex XC TS and Pro-Flex LP TS) from Ossur. Prospective, comparative study that included 10 trans-tibial prosthetic users walking with current foot design vs. the Pro-Flex XC/LP TS outcomes included the Prostheses Evaluation Questionnaire, Socket Comfort Scale, 6 MWT Performance, L-Test, Activities-specific Balance Confidence Scale and temporal spatial parameters of gait measured with original prosthetic device and the test devices used for 4 weeks. With the Pro-Flex XC TS and Pro-Flex LP TS, most subjects demonstrated average 10% increase in walking velocity, improved scores in the PEQ and 15% increase walking capacity. Improved L test time and swing/stance ratio. Most had improvement in the ABC, with small non-significant decrease was reported in 4 subjects. The newly designed Pro-Flex XC TS and Pro-Flex LP TS foot produce improvement in walking and functional rating as well as benefits in self rated performance and stability. This new foot design should be considered as and excellent choice for patients with functional ambulatory category 2–4. Tests of function and satisfaction should be used in future prosthetic foot trials and included in foot prescription.