Abstract
The purpose of this study is to examine the change in trunk muscle strength in judo athletes accompanying an increase in angle velocity, and to clarify the characteristics of lightweight and heavyweight athletes. Male collegiate judo athletes (16 lightweight and 17 heavyweight) and normal male college students (17) participated in the study. We used a CYBEX 770-Norm Trunk Extension/Flexion Unit to measure peak torque during trunk extension and flexion. The angle velocity was measured at 30, 60, 90, 120, 150 degree / second, according to CYBEX TEF standard protocol.
The results we achieved are as follows:
1. Peak torque during trunk flexion and extension at all angle velocities showed a high value (P < 0.01) for heavyweight, lightweight and normal students, in that order.
2. Peak torque during trunk flexion and extension for all groups showed the highest value at 30 degree / second, decreasing significantly (P<0.01) according to the increase in angle velocity.
3. With regard to peak torque during trunk extension, there was significant interaction (P<0.01) between the group and the angle velocity.
4. Moreover, in peak torque during trunk extension, the rate of decrease according to increase in angle velocity showed a low value for lightweight, heavyweight and normal students, in that order. At the highest angle velocity (150 degree / second), the lightweight athletes showed a significantly. (P<0.05) lower value in the rate of decrease compared with the other two groups.
These results suggested that the heavyweight judo athletes show a larger decrease in trunk extension force accompanying an increase in movement speed when compared with lightweight judo athletes.
