GENERATION OF LINEAR AND ANGULAR MOMENTUM DURING INTERACTION WITH DEFORMABLE SURFACES

Abstract

INTRODUCTION Generation of linear and angular momentum during goal directed movements involves regulation of the total body center of mass trajectory (CM) in relation to the reaction forces (RF) during contact with the environment. When interacting with energy-returning systems like a springboard, the performer is able store energy in the springboard during board depression for later use during the recoil phase. During the board depression phase of springboard dives initiated from a hurdle, no significant differences in CM trajectory in relation to the RF were observed between front (FS) and reverse (RS) somersaults (FS: rotate forward and translate forward; RS: rotate backward and translate forward). During the board recoil phase, between-task differences in angular impulse generation were achieved by modifying the relative orientation between the CM and the RF [1]. These results at the total body level, led us to hypothesize that no significant differences in multijoint control would be observed within subject during the board depression phases of the FS and RS, whereas significant differences in multijoint control would be observed during the recoil phase. We tested this hypothesis by comparing knee-hip coordination and muscle activation patterns during the take-off phase of the FS and RS dives performed by the same subjects.