[236] A measurement of isokinetic muscular strength during torso rotation in athletes

[Objective] The purpose of this study was to examine isokinetic muscular strength during torso rotation in athletes by using a Cybex TR machine. [Methods] The subjects were 10 weight lifters, 13 sprinters of track and field, 7 middle distance runners, 8 long distance runners, 10 archers, the age range was from 18 to 22 years old. We measured the peak torque of the torso rotation by using a Cybex TR (Torso Rotation) machine. The angular velocities were 0, 30, 60, 120, 150, 180 deg/sec. And we observed the movement of the muscle, M. sternocleidomastoideus, M. elector spinae, M. rectus abdominis, and M. obliquus externus abdominis, by using an EMG. [Results and Discussion] As the angular velocity increased, the peak torque of torso rotation showed a lower value for both right and left rotation in all athletes. The peak torque tended to show a higher value in the athletes with a high level of muscular strength, such as the weight lifters and the sprinters. The right and left torso rotation ratio was in the range of 1.0±0.1 in all athletes. Therefore, the data suggests that they have a good balance of right and left muscular strength. And it was observed by the EMG that the right M. elector spinae and left M. obliquus externus abdominis, and the left M. elector spinae and right M. obliquus externus abdominis, act as synergistic muscles.