Figure 1. Experimental set up to perform Wartenberg test.

(A) From the maximum extension of knee joint, the leg passively oscillates about the gravitational resting position. An electrogoniometer acquired the knee joint angle and two couples of surface electrodes recorded the EMG activity from the Rectus femoris and Biceps femoris caput longus. (B) Typical kinematic trajectory reporting the knee angle variations from the onset angle to the resting angle, and the main landmarks for further kinematic and dynamic computations. F1–F4, angles of reversal at the end of each swing flexion; E1–E4, angles of reversal at the end of each swing extension; PA, plateau amplitude.