Is movement variability relevant for the elite golfer? A biomechanical and modelling perspective

Movement variability, while being a topic discussed extensively throughout the movement sciences, is still not understood. The effect of movement variability on outcome has not been ascertained. In particular, there has been a dearth of research investigating movement variability in the golf swing. The objective of this thesis was to investigate the effect of movement variability on outcome and outcome variability. Using experimental methods, the initial aim of this thesis was to quantify movement variability of sixteen participants and investigate the relationship between the quantified movement variability and outcome variability in the golf swing. The results indicated no statistically significant relationship between movement variability and outcome variability either in the backswing or downswing phase of the swing. Following this, modelling methods were used in the investigation of movement variability on outcome in the golf swing. Firstly, a computer model of a participant’s golf swing was created and validated. Then a method to apply movement variability at single anatomical points to the computer model was developed. Subsequently, different levels of movement variability were applied to single anatomical points in the computer model. The results revealed there was no practical effect on outcome. In order to investigate movement variability of measures more complex than single anatomical points, the final stage of this thesis investigated the movement variability of a multi-segment measure, torso-pelvic separation angle. Torso–pelvic separation angle was quantified for all sixteen participants. The results revealed no significant relationship between movement variability in this measure and outcome variability. Applied movement variability in this measure to the validated computer model created previously, revealed no practical effect on outcome. Collectively, the results of this thesis indicate that movement variability has no effect on outcome beyond the natural variation range of the participant at the elite level of performance. These findings have implications for coaching the golf swing in that it is important for golf coaches to understand the effect of variability relative to shot outcome for each individual. At the elite level, advocating an invariant swing may not lead to a more consistent shot outcome.