Figure 1. Experimental set-up.

Subjects stepped on an inclined surface (I) in the middle of a 10 m walk-way. Knowledge of the platform's inclination was prevented by occluding part of the subject's view (grey area) with taped glasses (II). Ankle and knee rotation were recorded using goniometers (III) and Achilles' tendon force was estimated by an external buckle transducer (IV). Ensemble averaged (n > 20) electromyographic recordings from gastrocnemius medialis (GM) of a representative subject is presented for 0 deg (black), +3 deg and −3 deg (increase and decrease, respectively, in the EMG) degree inclination (V), showing modulation in muscle activity induced by the inclination of the platform.