ABSTRACT
Objective: This study aimed to clarify changes in planter pressure at the 1, 2, 5 metatarsal head, and muscle activities resulting from exercise of the peroneus longus (PL) or tibialis posterior (TP) muscles. Method: Nine subjects (3 male, 6 female) were recruited. Before and after exercise, planter pressure at the metatarsal heads and the activities of PL, TP, tibialis anterior, and soleus muscles were recorded during heel raising using electromyography and a foot sensor. The first exercise was a maximal isometric contraction of the PL and peroneus brevis (PB). The second was contraction of the TP, and the third was of all three, the PL, PB, and TP. Result: The amount of planter pressure at the first metatarsal head increased after PL exercise. The standard deviation at the second metatarsal head decreased after PL and TP exercise, but showed no change after PL exercise. Conclusion: After PL and TP exercise, heel raises were possible with few perturbations at the metatarsal head. After PL exercise, the amount of planter pressure at the first metatarsal head increased, but there was no change in perturbations. The results show that it is necessary to consider the effect of short time exercise.