Forefoot bending stiffness in the bobsleigh push-start

The purpose of this study was to investigate how forefoot bending stiffness (Kcr) changes with speed across the bobsleigh push-start. Kinematics and kinetics of 15 elite athletes were measured on an indoor track during different phases (Contact 1 & 2, 10 m, 30 m) of the bobsleigh push-start using a MoCap-System and three force plates. Metatarsophalangeal joint (MPJ) angles, moments and Kcr were calculated via MATLAB. In contrast to sprinting, maximum MPJ moments, moments at maximum MPJ dorsiflexion and Kcr showed no significant differences (p > 0.05) about the push-phase due to the inter-individual variations between the athletes. The forefoot mechanics of each athlete should be taken into account individually for performance enhancement strategies and the development of assistive devices like insoles or customized shoes.