2022 Volume 8 Issue 1 Pages 65-71
The peroneal muscles undergo morphological changes and functional decline after an ankle sprain, contributing to recurrence. We reported that different morphological changes occur in the peroneus longus (PL) and peroneus brevis (PB) after an ankle sprain (Arima et al., 2022), and we believe that selective muscle strength train for the PL and PB is necessary. This study aimed to examine whether the morphology of PL and PB is selectively altered by different training methods. Two tasks were performed on separate days: the ball of the foot task in which a Thera-Band was placed on the ball of the foot and pushed out from the contact point, and the fifth metatarsal task in which the Thera-Band was pushed out from the base of the fifth metatarsal. Muscle cross-sectional area (CSA) and muscle echogenicity of the peroneus muscles at 25% and 75% proximal to the line connecting the fibular head and the lateral malleolus, and ankle joint strength were measured before and immediately after the task and at 10, 20, and 30 minutes later. A repeated measures analysis of variance was used to compare each item measured at each time point. In the ball of the foot task, the CSA at the proximal 25% was significantly higher immediately and 10 minutes after the task than before (p<0.05). In the fifth metatarsal task, the CSA increased significantly in the proximal 75% after the task (p<0.05). Transient muscle hypertrophy immediately after training is due to edema caused by muscle injury, indicating an immediate effect of training (Damas et al., 2016). The CSA of the proximal 25% showing PL in the ball of the foot task and the distal 75% showing PB in the fifth metatarsal task increased immediately after the task, suggesting the possibility of selectively training PL and PB in this task.
