Premovement Silent Period of Erector Spinae and Reaction Times of Bulky Muscles in Ballistic Standing-up Movement
The appearance rate of premovement silent periods (PMSs) of the erector spinae and EMG-reaction times of the obliquus abdominis and quadriceps femoris were examined during fast ballistic standing-up movement in the normal adults and hemiplegics. The average appearance rate of PMSs in hemiplegics was lower than in normal subjects, but no significant laterality was observed in either groups. Reaction times of trunk muscles also showed no significant laterality in either the normal subjects or the hemiplegics. Considering the relation between the appearance rate of PMS and the motion velocity, the PMS did not seem to reflect the central processing efficacy itself, which can be evaluated by reaction time measurement. Electromyographic study of the PMS may provide an indicator of the central coordination mechanism of the trunk and extremities.
