Rotational biomechanics of the elite golf swing: benchmarks for amateurs.

The purpose of this study was to determine biomechanical factors that may influence golf swing power generation. Three-dimensional kinematics and kinetics were examined in 10 professional and 5 amateur male golfers. Upper-torso rotation, pelvic rotation, X-factor (relative hip-shoulder rotation), O-factor (pelvic obliquity), S-factor (shoulder obliquity), and normalized free moment were assessed in relation to clubhead speed at impact (CSI). Among professional golfers, results revealed that peak free moment per kilogram, peak X-factor, and peak S-factor were highly consistent, with coefficients of variation of 6.8%, 7.4%, and 8.4%, respectively. Downswing was initiated by reversal of pelvic rotation, followed by reversal of upper-torso rotation. Peak X-factor preceded peak free moment in all swings for all golfers, and occurred during initial downswing. Peak free moment per kilogram, X-factor at impact, peak X-factor, and peak upper-torso rotation were highly correlated to CSI (median correlation coefficients of 0.943, 0.943, 0.900, and 0.900, respectively). Benchmark curves revealed kinematic and kinetic temporal and spatial differences of amateurs compared with professional golfers. For amateurs, the number of factors that fell outside 1-2 standard deviations of professional means increased with handicap. This study identified biomechanical factors highly correlated to golf swing power generation and may provide a basis for strategic training and injury prevention.

Provision of enabling technology in professional sports.

Multiple-round golf tournaments are designed intentionally to separate individuals' scores as play proceeds. Variance analyses and consideration of individual differences (vs group mean effects) for a sample of professional events confirm that 3-, 4-, and 5-round tournaments show significantly increased variability (though stable means) from first to last rounds. It is argued here that the dispersion of scores increases as play proceeds because the more physically or mentally fit players emerge and continue to perform best. Furthermore, a marginal income analysis indicates that the average gain in earnings from a one-shot improvement in score is approximately $8,000. An interpretation based on fatigue, competition, and stress supports the Professional Golf Association's claim that provision of enabling devices, like a golf cart for disabled players, is also an enhancement and is thus unfair.

Effects of conditioning on physical fitness and club head speed in mature golfers.

The purpose of this study was to evaluate the effects of an 8-wk. conditioning program on selected measures of physical fitness and golf performance for 12 male and 5 female recreational golfers (M age = 52.4 yr., SD = 6.7 yr.). Measurements were made at baseline and following the intervention. The twice-per-week program consisted of strength training, flexibility, and plyometric exercises. Analysis of the pre- and posttest scores showed that conditioning was associated with significant increases in muscular strength, flexibility, and club head speed. Without a control group, the data suggest conditioning may be a worthwhile activity for mature golfers.