Abstract
This study aimed to examine fatigue of the quadriceps femoris after mountain climbing. Fifteen healthy adults participated in this study. We measured the strength and activity of the muscle at maximum voluntary isometric contraction (100% MVC). In addition, we recorded measurements at 4 different voluntary contraction strengths (10%, 30%,50%, and 70% MVC). The participants performed a task that involved isometric contraction during knee extension. The main outcome measures were muscle strengthandmuscle activity, assessed using a hand-held dynamometer and surface electromyography, respectively, for the right rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL). Fatigue of the quadriceps, especially the VM and VL, was observed after mountain climbing. The VM and VL, each of which is a single articular muscle, were possibly fatigued because they were repeatedly activated for weight bearing during mountain climbing.
