抄録
In this organized session entitled "An application of the sport and health science to the visualized form of in vivo information", we will demonstrate how to visualize the muscle activity in vivo by magnetic resonance imaging (MRI). It has been shown that transverse relaxation time (T2) weighted MRI of skeletal muscle demonstrates exercise-induced contrast enhancement that is graded with exercise intensity. This is because osmotically driven shifts of water fluid into the myofibrillar space. This study was conducted to show whether the exercise-induced MRI can distinguish the activity of small muscle such as intrinsic foot muscles. Eight subjects (age 22.4±1.1 years, height 173.1±2.7 cm, weight 64.9±4.3 kg) performed five sets of one-legged toe muscles were obtained and calculated T2 values by them. MRI is actually a noninvasive method and allows us to distinguish each muscle activity alternative to electromyography (EMG). T2 measurements of MRI can specifically provide direct information in each muscle activity.
