Determination of the H-reflex in the VL and extra forces of the quadriceps muscles. A, Stimulation of the Quad nerve in the inguinal region at low stimulation intensities (<1.5 T) evoked compound action potentials in the VL muscle that were abolished by stretching the semitendinosus (St) muscle, thus confirming that the response was an H-reflex. B, Latency of the H-reflex measured from stimulation onset to the first deflection of the EMG trace at a stimulation intensity of 1.1 T. C, Latency of the M-wave, measured from stimulation onset to the first deflection of the EMG trace, at a stimulation intensity of 3.0 T. D, Forces produced with top hat stimulations of the Quad nerve at 1.1 T at muscle lengths +10 and 0 mm from neutral. E, Force output generated by the Quad muscle group during and following vibration of the Quad tendon at a muscle length of +10 mm from neutral.