The effects of leg prosthesis stiffness and take-off board stiffness on long jump performance

Run-up velocity and take-off step technique influence long jump performance. We determined run-up velocity and jump distance of two athletes with transtibial amputation (TTA) who used a manufacturer-recommended stiffness running-specific prosthesis (RSP; 39.5 kN/m), and a less (36.0 kN/m) and more stiff RSP (43.9 kN/m) and eight non-amputee athletes who used a regulation run-up surface with a regulation (1630 kN/m), and two compliant (84.0 and 90.0 kN/m) take-off platforms. Athletes with TTA had no significant difference in maximum run-up velocity or jump distance between RSP stiffnesses, but jump distance was positively associated with run-up velocity (p = 0.002). Non-amputee athletes had no significant difference in maximum run-up velocity between take-off platforms but jump distance increased as platform stiffness decreased (p = 6.07 × 10^-5) and as maximum run-up velocity increased (p = 0.001). Non-amputee athletes jumped 7% farther when they used the most compliant compared to regulation take-off platform and had the same run up velocity (p = 0.82) but jumped 16% further (p = 0.01) than athletes with TTA using the recommended stiffness RSP despite the RSP storing 45% more elastic energy than the most compliant take-off platform (p = 6.73 × 10^-4). These results suggest take-off platform stiffness affects long jump performance in non-amputees.