Presentation
Does flexibility correlate with crunch factor in golf and produce faster clubhead speed?
The University of Notre Dame Australia
(2015)
Abstract
Introduction: Crunch factor (CF) in golf is the product of lateral bending of the trailing side and axial rotation velocity. CF is maximised at ball impact (BI) and is thought to increase force behind the ball and increase clubhead speed. Investigations have reported dissimilar findings on CF and low back pain although, flexibility and CF have yet to be assessed. The first aim of this study was to see if flexibility (absolute range of motion – ROM) enabled golfers to maximise CF at BI for trunk and lower trunk segments. The second aim was to see if absolute ROM variables helped to produce clubhead speed.
Methods: Fifteen male high-level amateur golfers (handicap = 2.5 ± 1.9) had their absolute ROM and five-iron golf swings analysed using a 10-camera 3D motion capture system, operating at 250 Hz. A validated multi-segment model was used to analyse kinematics (golf swing and absolute ROM) for trunk and lower trunk segments. A validated launch monitor was used to determine clubhead speed. A bivariate correlation analysis was used to investigate between-segment relationships for kinematic variables. Regression equations were used to determine which absolute ROM variables explained CF for each segment as well as which kinematic variables explained clubhead speed.
Results: Bivariate correlation analysis reported moderate correlations of lateral bending at BI and axial rotation velocity for both trunk and lower trunk CF. Five absolute ROM variables reported moderate positive and negative values with trunk CF, lateral bending of the trunk and lower trunk and lower trunk axial rotation at BI. Absolute ROM regression models reported lower trunk flexion and lower trunk CF as significant (p=0.006) variables to explain 57.4% variance for trunk CF. A non-significant significant (p=0.74) 22.5% model was generated for lower trunk CF. The regression model for clubhead speed reported trunk lateral bending at BI and lower trunk CF as significant (p=0.008) variables to explain 63.6% variance.
Discussion: Of the five absolute ROM variables, only lower trunk axial rotation was shown to be negatively correlated with CF variables. Trunk and lower trunk flexion and lower trunk left lateral bending were moderately positively correlated with CF variables. These results were reflected in the trunk CF regression model, suggesting flexibility is important in producing CF. However, although lower trunk CF was shown to be a significant variable in explaining clubhead speed, no absolute ROM variables were reported in the clubhead speed regression model.
Keywords
- golf,
- clubhead speed,
- injury,
- crunch factor
Disciplines
Publication Date
Spring October 10, 2015
DOI
http://dx.doi.org/10.1016/j.jsams.2015.12.351
Citation Information
Christopher Joyce. "Does flexibility correlate with crunch factor in golf and produce faster clubhead speed?" The University of Notre Dame Australia (2015) Available at: http://works.bepress.com/chris-joyce/13/