Physiological differences in sarcolemmal excitability between human muscles

Introduction The sarcolemmal resting membrane potential (RMP) affects muscle excitability, contractility, and force generation. However, there are limited In vivo data on the normal RMP of the human sarcolemma between muscles. We hypothesize that the in vivo RMP may differ between human muscles with different physiological roles. Methods Muscle velocity recovery cycles were recorded from a proximal antigravity muscle, the rectus femoris, and compared with paired recordings from a distal non‐antigravity muscle, the tibialis anterior, in 34 normal individuals. Results Significant differences in muscle relative refractory period (3.55 millseconds vs 3.87 milliseconds, P = .002), early supernormality (14.22% vs 10.50%, P