## Sunday, October 23, 2011

### Physics of the Giant Backwards Circle (A Complex Gymnastics Skill)

The Giant Backwards Circle (or "Giant" for short), is a circling skill that completes a 360 degree rotation around a single bar
How is it done?
1. Start in a handstand on top of the bar
2. Swing downward through the bottom of the bar
3. Then swing upward and end in the same handstand position
While this may look simple and sound easy, there is actually much skill involved in getting the technique right and overcoming the opposing physical forces
In order to complete this skill, the gymnast must overcome the opposing forces of gravity and friction. The force of gravity is overcome by a "tap", which is when the body bends at the shoulders at the bottom of the circle, thus shortening the radius. In doing so, the acceleration of the whole body increases, and if done correctly, it can be enough to overcome gravity. The force of friction between the gymnast's hands and the bar can never be eliminated. One's grip should be tight for 270 degrees of the skill and loose enough for the remainder of the circular motion to allow the entire body to rise to the handstand position at the top of the bar. Some quick tips for performing the giant correctly are to stretch the body on the downward swing to achieve enough momentum, to keep the head tucked "in", and to lift your toes as opposed to arching your back. While these methods may appear to increase one's rotation, their improper form could lead to serious injury.
Note in this picture that the body is in a hollow position for 330 degrees of the giant. In the 30 degrees at the bottom of the circle, the body is in an arch position due to the tap. It is important that the gymnast's shoulder be pushed straight for a majority of the giant, and they should only bend for a short period in order to increase their acceleration to get back to the handstand position on top of the bar.
For more information, see this website: http://www.gymnasticsrevolution.com/Parents%2021.html