Fig. 1

Experimental set-up. The participant’s foot is firmly attached to a force transducer interfaced with a laboratory computer. The forces exerted in the Y and Z axes are displayed as a cursor on a screen located beside the participant. The participant’s task is to exert progressive static exertion by moving the cursor within a corridor in eight successive directions. Plantarflexion is performed and trained using a unidirectional cursor displaced in proportion to the moment of force measured in the X axis