Abstract des Autors

A study was conducted to investigate the relationship between long latency activities evoked by a sudden muscle stretch of the right wrist flexor and a performance during a target match task accompanying wrist movement. The index of performance was the target match time (TMT) from onset of a handle displacement until the handle position output was matched with a target line. The standard deviation of TMT (TMT-S.D.) was calculated. Sixteen healthy men, ranging in age from 20 to 27 yr., participated in the study. A DC torque motor was used to generate an angular displacement at the right wrist joint. Analysis of the surface eletromyogram recorded from the wrist flexor showed that the short and long latency reflex components (M1, M2 and M3) were evoked by muscle stretching. In the target match task, the amplitude of the M2 and M3 components for all subjects were significantly smaller than the M1 component. In some subjects the M3 component was not identifiable, since its amplitude was very small in the target match movement. There were significant correlations between the M2 amplitude and performances during the target match task. In short, the smaller the M2 amplitude was, the shorter the TMT became and the smaller the TMT-S.D. became. These results suggest that the change in the M2 component is related to motor control for the target match task. Verf.-Referat