Analysis of Sit-to-Stand Movement by Measuring Floor Reaction Force

We conducted an analysis of sit-to-stand movement from a seated position of 20 healthy males by measuring floor reaction force. The aim of this study is to describe the floor reaction force pattern of normal sit-to-stand movement and to examine how the floor reaction force is influenced by a change of height of a chair, by a different position of feet, and by increasing trunk forward flexion. The floor reaction force pattern of normal sit-to-stand movement is characterized by two-peak pattern of vertical component which consists of a sequence of weight loading, weight releasing and weight loading. By changing height of a chair, it was found that the peak value of vertical component changed prominently. In the case of placing the feet anteriorly, the forward-backward component increased distinctly. Besides, we examined the movement of center of pressure in rising from a chair. Through these results, we considered about the kinesiology of normal sit-to-stand movement and its clinical application.