Study on Fluctuation in the Spectrums of Torque Data During Golf Swing Due to the Mass Difference of Golf Club Shafts

PurposeWhen golfing, using a suitable club is crucial to swinging as desired and achieving high scores. Various studies have analyzed golf clubs and swings to select an appropriate club. However, only a few have considered how variations in the club's physical characteristics change the swing. This study applied the short-time Fourier transform (STFT) to torque data obtained during swings to elucidate how the variation in shaft mass affects the swing, and verified the role of the torque by comparing it with the variation in shaft tip velocity.MethodsFirst, we used a motion capture system to record a golfer's swing with varied shaft masses and created a three-dimensional rigid-body dynamic model of the arms and club. Next, we obtained torque data during the swing using inverse dynamics calculations, applied an STFT, and investigated the frequency component variations in time. Finally, we examined the variation in the spectrogram values when changing the shaft mass and searched for common patterns among participants.ResultsThe results confirmed that an increment of the shaft mass causes the maximum value of the spectrogram to increase for some participants and decrease for others. Moreover, we compared the trend of change of the average of the spectrogram in the low- and high-frequency regions with that of the shaft tip velocity, identifying the torque component that most contributes to the latter.ConclusionBased on the results, we envision the possibility to suggest golfers a suitable shaft mass and movements that increase the shaft tip velocity.

Automated summary

This study used the short-time Fourier transform (STFT) to analyze torque data of golf swings and explored how variations in shaft mass affect the swing. The results confirmed that the shaft mass can influence the spectrogram values and the shaft tip velocity.