Preliminary Testing of Golf Swings using Qualisys 3D Motion Capture

Julia A. Gambill, Meredith K. Owen, Jordan Byrd, John D. DesJardins, Ph.D

Introduction

The golf swing is a dynamic movement that requires great attention to detail to consistently duplicate. Because of the complexity of the swing, brought on by the multiplanar movement and amplified by a desire for increased club speed, it is difficult to observe the motions that affect it. However, 3D motion capture has made it easier to. The purpose of this preliminary study was to determine the possible ways to evaluate swing consistency using the Qualisys 3D motion capture system for future studies.

Materials and Methods

In this preliminary study the Qualisys 3D motion capture system (Qualisys AB, Göteborg, Sweden) was used to determine the possible methods to evaluate swing consistency. This system utilized eight cameras to calculate predetermined infrared marker positions on experienced golfers (n=2). An elite golfer was selected for the preliminary study to perform several golf swings using an iron club. Once captured, an Automatic Identification of Markers (AIM) model was applied so the system could interpret the infrared markers on the golfer and formulate a skeletal model of the data acquired.

Once captured, an Automatic Identification of Markers (AIM) model was applied so the system could interpret the infrared markers on the golfer and formulate a skeletal model of the data acquired. The data was manually processed to ensure the markers were identified correctly and that each marker was captured over the full trial period. Following this, Qualisys created a skeletal model of the data that could be processed using Visual 3D which outputs numerical data, and Qualisys web report which produces graphical representations of the data.

Results

Initial analysis of the data indicated several areas of interest, specifically kinematic sequence. It describes the acceleration and deceleration of the proximal to distal segments of the golfer’s body during the swing to optimize club head speed. Commonly, the kinematic sequence is a target parameter to increase power in the golf swing (Lai). Within the kinematic sequence, the pelvis, torso, lead arm, and club will ideally have peak angular velocities in succession.

Standard deviations of the swing time in which each peak occurs will also be analyzed in order to determine consistency over several swings. Because each subject will have differing angular velocities, collecting standard deviation allows for the data to be analyzed across multiple subjects.

Conclusions

For the future study of consistency in golf swings using the Qualisys 3D motion capture system, kinematic sequence and standard deviations between swings will be analyzed. The benefit of improving the kinematic sequence in golf is to increase power and in turn increase club head speed to maximize ball distance. However, a golfer’s ability to replicate that power is just as beneficial, so standard deviations will be used to determine consistency of the swing over time.

Acknowledgements

I would like to thank the Summer CI & UR program as well as the Brooks Science Sports Institute for funding this research.

References

Lai D. Procedia Engineering, 2011, 13, 219-225.

Trial Swing with Reflective Markers

Hitting Bay Camera Setup

Qualisys Web Report

https://report.qualisys.com/r/PHzmGqGT6/details