Relationship between muscle strength ratio of quadriceps, inner hamstring and lateral hamstring and incidence of thigh muscle strains

Abstract

In order to find out the relationship between thigh muscle strains and the muscle strength ratios of the muscle strengths of the inner and lateral hamstrings and quadriceps femoris, we measured the knee flexion and extension strengths in the toe in, toe out and neutral positions of 27 university students participating in sports activities. The students were classified into two groups, those who had experienced thigh muscle strain (10 persons, injury group), and those who had not (17 persons, control group), and subjects' limbs were further subdivided into injured legs and uninjured legs in the injury group, and control legs (34) of the control group. Two students in the injury group, a field eventer and a volleyball player, had experienced quadriceps muscle strain, and there was a tendency for their quadriceps muscle strength on the injury side to be relatively weak. The muscle strengths of quadriceps and hamstrings of the eight students who had experienced hamstring injury, were higher than control legs in the injured legs. Especially, the hamstring muscle strength of those who had experienced lateral hamstring injury was stronger than that of control legs. We concluded that there is a possibility that the special movement characteristics of an event and relative weakness of the quadriceps muscle strength are factors in the incidence of quadriceps muscle strain, and that for lateral hamstring injuries, the role of regulation of contraction and relaxation in the counteraction to muscle movement is large, or its unpreparedness makes injury easier to occur.