Abstract
The purpose of this study was to analyse the functional roles of muscles as rising to a standing position from a sitting position on a chair recorded by the comprehensive system developed for the kinesiological analysis. The system was composed of a VTR set, a force plate, a surface EMG and an original mat switch that made those records synchronized.
Rising from the sitting position on a chair begins with trunk forward bending. The force of vertical reaction under the feet just decreased as soon as the rising movement started, and it then steeply augmented. The decrease in the force of vertical reaction was presumed that hip flexors and ankle dorsi-flexors active at the initial stage produced the force to lift up the lower extremities which was the same force to initiate the trunk forward bending.
