Instant feedback of dynamic release characteristics during golf downswing

Abstract

One of the most prominent features distinguishing skill levels of expert and amateur golfers is efficiency of swing movements. During the downswing, the release of wrist cock occurs as a result of bottom-up increase in segmental velocities, which is supposed to contribute to the efficient club head acceleration before the impact. Such dynamic properties are, however, hard to visually understand. In this paper, we evaluated the relationship between dynamic release characteristics and performance outcomes in a group of professional and amateur golfers, using an IMU-based swing analysis system (M-Tracer) and a radar-based ball tracking system (Trackman). Specifically, we measured (1) the elapsed time from the onset of release to the impact, (2) the angle between the direction of grip velocity and club shaft at the release onset, and (3) the carry distance of the ball. In all of the three measures, the professionals generally showed larger values with smaller variances than the amateurs. Based on these considerations, we developed a smartphone application to facilitate self-learning of efficient swing skills. Our application wirelessly collects data from the M-Tracer and a pair of pressure-sensing insoles (OpenGo) and provides an integrated feedback immediately after each shot. The appearance includes information regarding the release-related dynamic properties and the spatio-temporal foot contact patterns, enabling users to intuitively grasp how their swing can be more efficient.