A 3D analysis of golf swing kinematics, with a focus on relative shoulder and pelvis rotation, in different clubs

The X-Factor is the relative rotation of the shoulders with respect to the hips during the golf swing (Healy et al., 2011: Journal of Sport Science, 29, 1079-1088). It has been suggested that having a large X-Factor at the top of the backswing is one of the most important variables, but closing it rapidly during the downswing may also be as important (McLean., 1993: Golf Magazine, 1, 28-32). The aim of this study was to determine whether there is a difference in trunk kinematics, specifically relative torso-pelvic separation, between a variety of clubs. 3D kinematic data were collected from 11 low handicap (4.3±3.6) male golfers. Ten shots were taken with a Driver, a 4-Iron and a 7-Iron. Data were collected using a 6-camera motion capture system (Motion Analysis Corporation, Santa Rosa, CA), operating at 400Hz. Ball characteristic data were collected using a real-time launch monitor (Vector Pro Launch Monitor, Accusport International, North Carolina, USA). A within-measures ANOVA revealed no significant differences between clubs for group mean X-Factor (p=0.320) and X-Factor Stretch (p=0.334). Paired sample t-tests revealed significant differences between X-Factor and X-Factor Stretch between all three clubs (Driver p=0.0001; 4-Iron p=0.0001; 7-Iron p=0.0003). This study gives knowledge to practitioners in both coaching and strength and conditioning fields, in relation to the golf swing across a range of clubs, and a range of golfing abilities. Future studies should consider giving a more in depth analysis of relative torso-pelvic separation, throughout the whole swing, for a variety of clubs.