Mathematical comparison of swing planes with and without Explanar trainer

The golf swing has been modeled as a planar activity, but Coleman and Anderson (2007) found that the club does not move in a single plane during the downswing. The Explanar® training device aims to teach every golfer to swing on their ‘optimum swing plane’, but there has been little research on whether a golf swing performed on the Explanar® mimics that of an expert swing when analyzed three-dimensionally. Therefore, eight golfers (mean handicap 5.1) performed swings with a 6 iron and then on the Explanar® whilst being filmed with two video cameras at 50 Hz. Three-dimensional motion of the club from take-away to impact was calculated and the plane of the golf club motion was then computed. Plane angles to the horizontal were found not to be significantly different between the normal swing and Explanar® for the whole swing, downswing or backswing. However, plane angles to the target line were significantly different between the normal swing and Explanar®. Fit of the two swings to a single plane model were not significantly different except for the r.m.s residual values for the backswing. Changes in plane angles throughout the swing were also calculated and these showed large differences between the two swings for some golfers. These results suggest that the Explanar® may mimic some aspects of the swings of good golfers, but may omit some other important features.