自動化水準の異なる下肢の周期運動に対する上肢運動の干渉

抄録

The voluntary exercises consist of different automatized levels and are mostly a combination of the upper limbs and the lower limbs exercises.
This study was to examine the interference of the upper limbs exercise to the periodic lower limbs exercise with different automatized levels. Seven male university students, aged 19 and 20 yrs., served as subjects. The periodic lower limbs exercises were the stepping (walking on the place) and the alternate plantar-flexion of the right and left foot while standing. The frequencies of the lower limbs exercises were 120, 160 and 200 times/min, The stepping, which is similar to the motion of the lower limbs in walking or running, may be performed more frequently in daily life than the plantar-flexion in which only the ankle angle was changed. Therefore, we assume that the stepping is a higly automatized exercise compared with the plantar-flexion. Upper limbs exercise, which was combined with the lower limbs exercise, was the simultaneous tapping of one time by both hand. The interference degree was evaluated by the change of step intervals of the lower limbs exercise. The results were:
1) The fluctuation of step intervals on the plantar-flexion was greater than the fluctuation on the stepping and the smallest in the frequency 120 compared with that in the other frequencies.
2) When the tapping was combined with the lower limbs exercises, one step interval at that time was lengthened and one step interval immediately before the tapping was shortened. This change of step intervals was greater in the plantar-flexion than that in the stepping. The change in the plantar-flexion was the smallest in the frequency 120 compared with that in the other frequencies.
The above mentioned findings suggest that the automatized level of the lower limbs exercise can be clearly evaluated by the interference degree of the upper limbs exercise to the periodic lower limbs exercise.