Biomechanical analysis of kinematics in the single whip movement of Tai Chi using video imaging

“Single whip” is a typical movement in Tai Chi, and the study of its kinematics has important practical value for better understanding the laws and characteristics of Tai Chi movements. This study divided 30 Tai Chi practitioners into two groups based on their skill level: an excellent group and a beginner group. The Vicon motion capture system and a three-dimensional force platform were used to obtain kinematic data. Differences in movements between the two groups at various stages were compared. The results showed that the excellent group took longer in stages one and three, but shorter in stage two. In stage one, the left knee joint angle of the excellent group was 95.45° ± 16.02°, while the right knee and left hip joint angles were larger (148.62° ± 12.84° and 133.55° ± 18.61°). In stage two, the angles of the right knee, left ankle, and right ankle joints of the excellent group were significantly smaller than those of the beginner group. In stage three, the angle of the right elbow joint of the excellent group was larger (154.26° ± 12.06°), while the angles of the right wrist angle and the left and right ankle joints were significantly smaller than those of the beginner group (p < 0.05). In terms of vertical displacement of the center of gravity, the excellent group exhibited less fluctuation and significantly lower dynamic stability in both anterior-posterior and medial-lateral directions compared to the beginner group (p < 0.05).