The ankle jerk and the tibial H-reflex: a clinical and electrophysiological correlation.

In an attempt to correlate the tibial H-reflex with the ankle jerk, we evaluated 130 reflexes in 65 patients (35 men and 30 women). All the ankle jerks were graded by one of the authors (BK) without the knowledge of the H-reflex results. The maximal H-reflex amplitude, and the maximal H/maximal M amplitudes correlated in a positive fashion with the ankle jerk (r = 0.75 and 0.69 respectively). In contrast, there was no correlation between the H-reflex latency and the ankle jerk (r = -0.11). We conclude that, in most situations, the tibial H-reflex amplitude and the ankle jerk correlate well; their discordance is infrequent (11.5%).