Physiological Measurements of Walking and Running in People With Transtibial Amputations With 3 Different Prostheses

STUDY DESIGN: A 3-factor (foot type, speed, and mode of ambulation) repeated-measures experimental design was used. OBJECTIVES: To compare the differences in energy expenditure, gait efficiency, and relative exercise intensity in persons with transtibial amputations with various prostheses. BACKGROUND: There is a need for improved prosthetic designs to accommodate physically active persons with lower-extremity amputations. METHODS AND MEASURES: We used progressive speeds of treadmill walking (53.64, 67.05, 80.46, 93.87, and 107.28 m/min) and running (120.69, 134.1, and 147.51 m/min) with 3 different types of prostheses: the Solid Ankle Cushion Heel (SACH) foot, the Flex-Foot (FF), and the Re-Flex Vertical Shock Pylon (VSP) prosthesis. Five physically active men with unilateral transtibial amputations served as subjects (aged 31.6 +/- 4.28 years). RESULTS: The following statistically significant differences (improvements) between the Re-Flex VSP versus the FF and the SACH foot were found. Energy cost: walking (5%), running (11%); gait efficiency: walking (6%), running (9%); relative exercise intensity: walking (4%), running (5%). However, we found no significant differences between the FF and the SACH. CONCLUSIONS: The Re-Flex VSP appears to have a positive effect on energy cost, efficiency, and relative exercise intensity compared with the other prosthetic foot types during walking and running.