Biomechanical Analysis of the Sit-to-Walk Series of Motions Frequently Observed in Daily Living: Effects of Motion Speed on Elderly Persons

It is important to clarify the normal biomechanical characteristics of the sit-to-walk (STW) series of motions clear for healthy elderly people. Clarifying the biomechanical characteristics of normal motions is necessary to be able to develop an appropriate intervention to improve physical functions. Eight healthy elderly people performed STW motion at the two patterns of speeds: a fast condition and a slow condition. Kinematic and kinetic data were obtained. Maximal anterior ground reaction force was significantly larger in the fast speed condition. In the fast speed condition, the subjects initiated gait with the hip and knee more flexed. And the center of pressure (COP) moved forward gradually constraining the forward movement of the center of the gravity (COG). In the slow speed condition, the COG movement was slower, so the COP moved backward in order to induce a forward COG movement. In the fast motion it is important to accelerate and control the forward movement of the body.