Abstract
This paper describes a comparison between the three dimensional trajectory of elbow measured by an imega analyzing system (IAS) and that using body-mounted sensor system (3D sensor) proposed by the authors during pitching. The 3D sensor derives 3D trajectory of elbow by the double integration of the 3D body acceleration which is acquired by 3D accelerometer with the sampling frequency 1000[Hz]. Since the derivation of the 3D trajectory is effected by the duration of the double integration, the difference and the correlation coefficient of two trajectories between the IAS and the 3D sensor are calculated by changing the beginning and the end of the integration. Moreover, the condition of acceleration and the angular velocity that minimizes the difference and maximizes the correlation coefficient is investigated. The calculation results show that the size of the angular velocity determines the duration of the double integration to estimate feasible trajectory of the elbow during pitching.
