The Effect of Strength Training of Medial Quadricep and Hamstring on Muscle Thickness and Quality

This study aimed to examine the effect of medial quadriceps- and hamstring-focused strength training on muscle morphology and quality. Ten males and ten females participated in an eight-week strength training program for their medial quadriceps and hamstrings. The ultrasound images of medial/lateral quadriceps and hamstrings were collected before and after this program. Both muscle thicknesses and echo intensity parameters of all measured muscles showed high reliability coefficients. The muscle thickness of medial quadriceps and hamstrings significantly increased post training for both males and females, whereas no difference was observed in the muscle thickness of lateral quadriceps and hamstrings. The echo intensity of medial thigh muscles decreased for both males and females; however, there was no significant difference in the echo intensity of the lateral thigh muscles. Therefore, medial quadriceps- and hamstring-focused strength training can strengthen the medial thigh muscles selectively, and hence can be considered in ACL injury prevention programs.