Figure 8

The profile of the anterior-posterior COP position and joint moments. Time = 0 indicates the instance when the buttocks lost contact with the chair. All graphs are drawn until the end of each STS movement. The upper end of the graph indicates tip toe position (line-1). The lower limit of the same graph indicates the heel position (line-3). The intermediate line indicates ankle joint position (line-2). Joint moments are the values for one leg. Peak hip and knee joint moments reached their maximum near the initial position. At the ankle, joint moments tended to increase or decrease in synchrony with the changes in the anterior-posterior position of the COP. At the early stage of the movement, the hip joint moment exhibited the highest value when the joint moment index was |M_K|. The magnitude of the hip joint moments decreased in order from |M_A|, |M_H + M_K + M_A| and |M_H|, respectively. In the case of the knee joint moment, the order was the opposite.