Abstract
The purpose of this study was to investigate the effects of the weight of somatosensory inputs from lower extremities on postural control during standing on an unstable board. Ten healthy young males participated in this study, and they were divided equally into two groups based on their estimation of the weight of somatosensory cues from lower extremities. The subjects stood on the unstable board that has short support surface in anterior-posterior direction. Kinematics and ground reaction force data were collected, and coherence analysis was conducted between the leg and trunk angular displacement time series. The results showed that the subjects who weight somatosensory inputs have higher coherence and gain, and that indicated the coupled control between leg and trunk movements. On the other hand, the results of the subjects who less weight somatosensory cues showed that lower coherence and gain. The results indicated that movements of lower extremities and trunk were controlled independently, and that the subjects had relatively high weight of vestibular inputs. Thus, it was concluded that the control strategy during standing on the unstable board was influenced by the weight of somatosensory inputs from lower extremities.
