Effects of the type of holds and movement amplitude on postural control associated with a climbing task

The aim of the present work was to characterize the modifications of the postural adjustments during a climbing task as a function of postural and/or movement constraints. The variations of the horizontal and vertical forces and momenta were analyzed for different movement amplitudes and types of holds. The results show that the horizontal momentum is influenced by all experimental conditions before the onset of movement. By contrast, the vertical momentum is only influenced by the amplitude of the movement, after its onset. These results confirm the hypothesis of a dual function of the anticipatory postural adjustments. The horizontal momentum is mainly involved in the control of equilibrium. The vertical momentum contributes to the movement initiation.