A force and torque analysis of giant swings on the horizontal bar

The purpose of this study was to make a kinetic comparison of backward and forward giant swings on the horizontal bar. Six Canadian gymnasts of national calibre were filmed using a high speed camera during the performance of giant swings on a horizontal bar which was equipped with strain and torque gauges. Prior to filming, the horizontal bar was calibrated by force application at various angles. During the performances, voltage outputs representing force and torque were amplified and recorded on tape. The force/torque data were then subjected to computer analysis. Forces were plotted circularly against the angle at which the forces acted on the bar using an x-y plotter. Maximum forces and torques for both forward and backward giant swings were compared. Polar force plots were then normalized by dividing force by body weight. A superposition of curves for 11 backward giant swings and 12 forward giant swings has produced two models representing good performance of giant swings by national gymnasts. Deviations from the models may be useful in correction of errors in execution of the swings. This method could provide instantaneous feedback on performance technique without requiring film analysis.