Joint motion monitoring by accelerometers set at both near sides around the joint

In this paper we examined a joint motion monitoring method utilizing accelerometers to monitor upper limb motion in daily activities. In this method two accelerometers are set at both near sides around the joint. The difference of these sensor outputs depends on the joint angle because centrifugal and turning acceleration occurring in the rotation around the joint can be neglected. We confirmed the validity of this method in the measurement of elbow and shoulder motion.