Statistical parametric mapping analysis of upper limb joint coordination and variability differences during the downswing phase of the golf swing.

Objective: The aim of this study was to use statistical parametric mapping (SPM) to investigate differences in upper-body joint coordination and variability between golfers with low and high handicaps during the downswing phase. Methods: Fourteen right-handed male golfers each from the low and high handicap groups were recruited. Kinematic data were collected by Vicon 3D motion capture system. Visual3D software calculated joint angles and angular velocities. Customized Matlab scripts computed joint coordination and variability curves. SPM-based independent samples t-tests analyzed differences in upper limb joint coordination and variability during the downswing phase between groups. Results: In joint coordination, the low and high handicap groups differed in two couplings. In the left elbow (sagittal plane)-left wrist (sagittal plane) coupling, the low handicap group exhibited left elbow dominance, whereas the high handicap group showed left wrist dominance ( Conclusions: (1) Regarding joint coordination, the high handicap group exhibited earlier wrist engagement in the early downswing and a more pronounced tendency toward inverse motion between adjacent joints. (2) Regarding coordination variability, the high handicap group showed lower variability in elbow-wrist joint coupling during a brief interval at the end of the downswing. However, as this result was no longer significant after Bonferroni correction, it should be interpreted cautiously as a preliminary finding.