Three-dimensional joint moments analysis in a vertical quadrupedal posture associated with a leg release

This study reports on rock climbers biomechanical adjustments following a leg release from a quadrupedal vertical initial stance. Six climbers of international level have been studied. They were asked to maintain a quadrupedal posture on artificial holds equipped with strain gauges and then to release their right foot. The results show that all the rock climbers adjust differently the vertical forces and the horizontal forces on the holds. They distribute the vertical forces over the three remaining holds and the horizontal forces over the controlateral holds. A quasi-static three-dimensional multi-segment model was used to produce the net reaction forces and joint moments at each joint. Moment results enhance the role of the controlateral limbs, particularly the left leg. The gravity seems to be counteracted at the left knee joint, while body balance seems to be managed at the left hip and ankle joints.