Kinematic analysis of human upper extremity movements in boxing.

Using two synchronized cameras, four experienced boxers were filmed while they threw a series of punches at a practice bag. Three-dimensional (3D) coordinates of each boxer's shoulder, elbow, wrist, and glove were used to estimate linear and angular kinematics of the upper extremity. Average velocities at contact ranged from 5.9 to 8.2 m/s with peak velocities of 6.6 to 12.5 m/s reached 8 to 21 ms prior to hand/grove contact with the bag. Significant differences in shoulder and wrist velocitie, elbow angle excursions, and elbow angular velocities were seen when comparing hooks and jabs. Few differences were evident when comparing the kinematics of gloved versus bare-handed punches. Results are significant in providing kinematic data characteristic of experienced performers, which may be used in a kinetic model of punch impact and its relationship to potential injury mechanisms.