Removing swing from a handstand on rings using a properly timed backward giant circle: a simulation solution.

In the rings event in men's gymnastics, marks are deducted if the rings and gymnast are swinging during a held handstand position. The unwanted swing can be reduced in the next handstand position if the gymnast is able to properly time the start of the connecting giant circle. The purpose of this study was to search for the optimal time to commence a backward giant circle in order to attenuate swing in the succeeding handstand. Computer simulations, using a four-segment and a three-segment model which employed two-pulse muscular control strategies, were used to search for the optimal timing solution. Qualitative validation tests between the performance of a world class gymnast and the simulation models indicated that a three-segment model comprising a cables-rings segment, an arms segment with a shoulder torque generator, and a head-torso-legs segment, produced similar results to that of a four-segment model which separated the legs segment from the torso and employed an additional torque generator at the hip joint. The results from the simulation indicated that a gymnast should be advised to initiate a backward giant circle when his swinging handstand has reached the bottom of its swing-arc. For a handstand with an original swing-amplitude of 10 degrees, the simulation results indicate that a properly timed backward giant circle can reduce this amplitude to a negligible 1.5 degrees of swing.