Abstract
Estimation method of three-dimensional (3D) motion of upper limb, trunk and shoulder torque during pitching using body-mounted sensor is discussed The body-mounted sensor is composed of 3D accelerometer and 3D gyroscope with different dynamic range and is attached on upper arm, forearm and chest. The 3D trajectory is obtained by numerical integration of acceleration and angular velocity. Initial posture of the subject such as setup position is derived by performing four pre-determined movements^ rotation of whole body around vertical axis, flexion and extension of elbow, adduction and abduction of shoulder and keeping upper limb on suspending. Shoulder joint torque is estimated as internal/external torque, adduction/abduction torque and varus/valgus torque. Three subjects participated in the pitching experiment and the experimental results show that estimated 3D trajectory is highly correlated with that from motion capture system and shoulder torque is reasonably estimated.
