Estimation model of body acceleration of crutch users based on body parts movement

For an evaluation of walking motions, a body acceleration is considered to be an important measure. The reason is that, if the walking motion is stable, the body acceleration usually shows almost periodic patterns, and if not, it does not. Therefore, it is thought that, for an evaluation of crutch walking motions, the crutch user's body acceleration would be required. That is, unstable crutch walks result in aperiodic body accelerations, and it may cause the users falling. In this research, an instruction system of a crutch walking for untrained patients has been developed. The body accelerations are usually measured by acceleration sensors being attached on the walker's body. Therefore, the sensor systems may disturb smooth walking motions. In addition, it is desirable that commonly available sensors can be utilized for measurements of the walker's body accelerations without anything attached on the body. Therefore, in this paper, a novel acceleration measurement method, i.e., a body-part movement-based acceleration measurement method, was proposed for crutch users. For this purpose, several participants' crutch walks were measured by both an optical motion capturing system and an acceleration sensor system, and multiple linear regression analyses were applied for the acceleration data. As a result, an estimation model with the body acceleration was derived.