Comparison of centre of gravity and centre of pressure patterns in the golf swing

Analysing the centre of pressure (COP) and centre of gravity (COG) could reveal stabilising strategies used by golfers throughout the golf swing. This study identified and compared golfers' COP and COG patterns throughout the golf swing in medial-lateral (ML) and anterior-posterior (AP) directions using principal component analysis (PCA) and examined their relationship to clubhead velocity. Three-dimensional marker trajectories were collected using Vicon motion analysis and force plate data from two Kistler force plates for 22 low-handicap golfers during drives. Golfers' COG and COP were expressed as a percentage distance between their feet. PCA was performed on COG and COP in ML and AP directions. Relationships between principal component (PC) scores were examined using Pearson correlation and regression analysis used to examine the relationship with clubhead velocity. ML COP movements varied in magnitude (PC1), rate of change and timing (PC2 and PC3). The COP and COG PC1 scores were strongly correlated in both directions (ML: r = 0.90, P < .05; AP: r = 0.81, P < .05). Clubhead velocity, explained by three PCs (74%), related to timing and rate of change in COP_ML near downswing (PC2 and PC3) and timing of COG_ML late backswing (PC2). The relationship between COP_ML and COG_ML PC1 scores identified extremes of COP and COG patterns in golfers and could indicate a golfer's dynamic balance. Golfers with earlier movement of COP to the front foot (PC2) and rate of change (PC3) patterns in ML COP, prior to the downswing, may be more likely to generate higher clubhead velocity.