抄録
To understand the functional differentiation between dominant and non-dominant limbs in human upright standing, electromyographic (EMG) activities were analyzed while subjects stood on a rocking platform. EMG activities were recorded from ankle and knee joints muscles of both limbs. Subjects were instructed to stand on the rocking platform so that they rocked in the saggital plane. Movements of the platform, equivalent to fore and back movements of the subjects, were recorded by a force plate (center of pressure, COP). Mean EMG amplitudes of ankle extensors (m. triceps surae, GS) and flexor (m. tibialis anterior, TA) were higher in the dominant side than in the non-dominant side. Nevertheless mean EMG amplitudes of knee joint muscles were rather complicated; some muscles of the dominant side could show lower amplitude than those of the non-dominant side. When the COP marked the most fore and back points, muscles of the front side and those of back were activated 50-300 msec prior to the respective times. Between dominant and non-dominant limbs, the activities of the dominant muscles preceded about 10 ms to those of the non-dominant ones. It was supposed that dominant limb muscles were primarily used in dynamic postural control of human upright standing. [Jpn J Physiol 55 Suppl:S176 (2005)]
