Comparison of thigh muscle characteristics between older and young women using tensiomyography

Abstract

Tensiomyography is a non-invasive method of evaluating neuromuscular function through skeletal muscle contraction. The objective of this study was to compare the thigh muscle characteristics of older and young women using tensiomyography. Nineteen older and fifteen young women without musculoskeletal diseases were included. For the quadriceps, the bilateral vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) and for the hamstrings, the bilateral semitendinosus (ST) and biceps femoris (BF) were measured. Result variables--maximal displacement (Dm), contraction time (Tc), and contraction velocity (Vc)--were compared. Dm values of the hamstrings of both legs and their summed values were significantly smaller in older women than in young women; no difference was found in the Dm values of the quadriceps. Tc and Vc of the hamstrings, VM, and VL were longer and slower, respectively, in older women than in young women. There were no significant differences in the Dm, Tc, or Vc of the RF between older and young women. Decreased Dm of the hamstrings in older women occurred due to changes in muscle function, but not muscle mass. The changes in the Tc of the hamstrings, VM, and VL indicate that type II muscle fibers were converted to type I in older women. There was no difference in RF between older and young women, implying that the RF is not affected by age. Our findings indicate that resistance exercises, which preserve the type II fibers, and flexibility exercises, which reduce stiffness, are appropriate for the lower extremity in older women.