Abstract
While the major cause of a slice in an outside-to-inside (OI) golf swing path, the actual biomechanical role is unclear. With 85% of amateurs and 70% of the entire golfing population who slice the ball, it appears necessary to examine what causes the OI swing path. The purpose of this study was to determine the cause of the OI swing path by examining joint angles of the shoulders and elbows as well as the X-factor at different phases of the golf swing between two swing paths (normal (N) and 01).
Fourteen experienced male golfers (21.4 ±2.2 years, 22.2 ± 7.7 handicap) were recruited from California State University, Sacramento. Subjects hit foam golf balls off artificial grass and a rubber tee. Six golf swings (3 normal, 3 01) were used for analysis. Bilaterally, the angles of the shoulders and elbows, as well as the X-factor were points of interest at 6 different phases of the golf swing ( address, backswing, peak of the backswing, downswing, impact, follow-through).
A paired samples t-test with a bonferroni adjustment (p=0.0 1) indicated a significant difference at the right elbow during the backswing phase (N = 50.9° ± 10.6°, OI = 57.7° ± 10.5°). The increased elbow flexion indicates the golfers are taking the club too far inside, which decreases the amount of space between the hands and head at the peak of the backswing, resulting in an 01 downswing due to early extension of the elbows to create more space to swing the club. Ball flight characteristics for the N swing path resulted in 76% of balls hit straight, 14% hooks, and 10% slices. The 01 swing path produced 57% hooks, 26% slices, and 17% straight. These results suggest that the swing path is not the only determinant of a slice. It is how the swing path and club-face interact at impact which determines the direction of ball flight.