Abstract
The purpose of this study is to investigate role of extension-flexion movement (Reactive Action) on exertion of flexor muscular strength in the upper arm.
There were three types in the reactive actions based on the different activities of flexor muscles. First type (Type I) was obtained when the load (1006 P0, 30% P0) applied in the flexor. Second type (Typ II) was obtained when the flexor started to contract after being quikly stretched. Third type (Type III) was obtained with the same manner as Type II, but flexor was stretched more slowly.
Effect of each type movements were compared its power and velocity with the results obtained by flexion movement (Control) from the same angle, which the elbow extended in 3 type movements.
1) The power was the largest in Type III, the ratio of reactive action/control was significant. (p<0.05)
2) In comparison the velocity in reactive action with it in control, Type II was faster.
3) These results suggest closed relationship between the flexor activity and the velocity in elbow extension. The each extension velocities was in order that, Type II, I and III.
4) Two kinds in the EMG of triceps were obserbed in Type II. One activated triceps in extension, but the other. But the extension velocity was slower the faster.
5) The characteristics of extension in all subjects were investigated by EMG during elbow extension. The EMG of extensor had two kinds as the same as Type II. During the relaxation, the extensor remained weak discharge in the subjects, who the extensor activity was recognized in Type II.
These results should suggest that there are different muscular activities in order to exert the power and velocitty.
