Differences in shaft strain patterns during golf drives due to stiffness and swing effects

Abstract

There is much debate around the role of shaft stiffness in the dynamic response of the club shaft during the golf swing. This study used a novel complex analysis to investigate within-and between-golfer differences in shaft strain patterns for three shaft stiffnesses. Twelve right-handed male golfers, with a handicap less than or equal to five, hit six shots with three driver clubs which differed only in shaft stiffness. Clubs were instrumented to record the shaft strain in the lead/lag and toe/heel directions. The analysis combined these perpendicular components into a single complex function, which enabled the differences between two swings to be characterised by a scale and a rotation component. Within-golfer strain patterns were found to be significantly more consistent than between-golfer, p < 0.01. Whilst some golfers displayed more similar patterns than others, there were no clear groups of golfers with similar patterns of shaft strain. Between the clubs, shaft strain patterns differed in the scale component, p < 0.01, rather than the rotation, p = 0.07.

The Role of Emergent Technologies in the Dynamic and Kinematic Assessment of Human Movement in Sport and Clinical Applications

“…In golf, more flexible shaft bending during the golf swing has a direct effect on making a more significant contribution to clubhead speed due to increasing the angular velocity at the grip. Via embedding the strain gauge inside the shaft of the golf stick, the data of the magnitude of shaft strain during the swing, rotation, and change in the shaft strain profile are accessible to aid in providing custom-fit clubs to golfers [78].…”

Investigating the Influence of Shaft Balance Point on Clubhead Speed: A Simulation Study

“…To provide control over the effects of stiffness, all shafts were given the same stiffness profiles. A constant elastic modulus 𝐸 = 68.9 GPa was used for shaft A to provide an average rigidity 𝐸𝐼 = 50 Nm 2 , which is representative of a regular-flex shaft [4]. For shafts B and C, the elastic moduli were varied along the shaft to generate the same bending stiffness profile as shaft A.…”

“…Previous studies investigating the golf shaft's role in generating clubhead speed have focused primarily on shaft stiffness [1][2][3][4]. These studies have brought attention to the physical interaction between the shaft and golfer biomechanics, which is not easily understood.…”