Abstract
[Objective] The purpose of the present study was to examine the relationship between the thickness of vastus intermedius muscle (VI), knee extension force, and grip force in healthy young women. [Subjects] The subjects were15healthy young women. [Methods] The knee extension force in sitting position, the muscle thickness of rectus femoris (RF), vastus medilis (VM) and VI, and the grip force were evaluated in the present study. Pearsonʼs product-moment correlation coefficient was used for the relationship between the muscle thickness and force. [Results] We found that the knee extension force was significantly correlated with the muscle thickness of VI, but not with that of RF. On the other hand, the grip force was significantly correlated not only with the knee extension force but also with each muscle thickness of RF, VI, and VM. [Conclusion] These results indicate that the muscle thickness of VI is more appropriate to speculate the knee extension force, because VI has a greater contribution to the knee extension movement than RF, In addition, grip force could reflect the lower limb and/or other muscle strength.