Quantitative Motion Analysis of Tai Chi Chuan: The Upper Extremity Movement

The quantitative and reproducible analysis of the standard body movement in Tai Chi Chuan (TCC) was performed in this study. We aimed to provide a reference of the upper extremities for standardizing TCC practice. Microsoft Kinect was used to record the motion during the practice of TCC. The preparation form and eight essential forms of TCC performed by an instructor and 101 practitioners were analyzed in this study. The instructor completed an entire TCC practice cycle and performed the cycle 12 times. An entire cycle of TCC was performed by practitioners and images were recorded for statistics analysis. The performance of the instructor showed high similarity (Pearson correlation coefficient (r) = 0.71 ~ 0.84) to the first practice cycle. Among the 9 forms, lay form had the highest similarity (r_mean = 0.90) and push form had the lowest similarity (r_mean = 0.52). For the practitioners, ward off form (r_mean = 0.51) and roll back form (r_mean = 0.45) had the highest similarity with moderate correlation. We used Microsoft Kinect to record the spatial coordinates of the upper extremity joints during the practice of TCC and the data to perform quantitative and qualitative analysis of the joint positions and elbow joint angle.