Abstract
A study was conducted to investigate the characteristics of motor control from the view points of stretch reflexes and premotor time in kendo players as compared with sprinters and non-athletes. A DC torque motor was used to provide a sudden muscle stretch stimulus at the right wrist flexor. The subjects were asked to do a reaction movement during wrist flexion to the muscle stretch. We measured the modulation of long latency stretch reflex (M2 component) and premoter time during reaction movement by the analysis electromyogram recorded from the wrist flexor.
The main results were as follows
1) The premotor time in kendo and sprinter groups were significantly shorter than in non-athlete group.And there wasn't significant difference between kendo group and sprinter group.
2) In all subjects, the amplitude of M2 component increased during flexion reaction movement. The increasing rate of M2 amplitude in Kendo group was significantly larger than in other groups, and it in sprinter group was significantly larger than in non-athlete group.
3) When the kendo players were classified into two groups according to kendo performance, the increasing rate of M2 amplitude in the higher performance group was significantly larger than in the lower performance group, but the difference in premotor time between the two groups was very insignificant.
From these results, it became clear that the kendo player can effectively control the amplitude of long latency reflex for reaction movement as well as he can do a quick reaction, and suggested that a degree of change in M2 amplitude from wrist flexor reflects the characteristics of motor control in kendo players.
