Stay Tight! (Part II)
If you remember from last time, we're taking a technical look at the reasons for needing to stay tight in gymnastics. This time around we're going to examine the mechanics of twisting, which occurs in pirouettes and several tumbling tricks.
There are two main things to keep in mind when doing any turning around the vertical axis of your body (a pole, for example, running from your head, along your backbone, and down to your feet): 1) twisting as a whole and 2) conservation of angular momentum.
First off, let's think about how objects turn. Ask yourself: will your body turn faster if it twisted as one tight mass, or if you were loose and twisted from your waist? If you can visualize the latter situation, you will notice that your upper body will begin turning around your vertical axis while the rest of your body stays where it was. Soon, you will reach the point where your upper body can turn no more. This is when your lower body begins to twist. But this start-stop motion is inefficient. Some of the momentum gets lost when your upper body suddenly stops. Only a tiny portion of it transfers to the movement of your lower body. The result? As soon as your lower body catches up with your upper body, you stop turning.
Go ahead and try just a pirouette on the floor. Swing your arms around you to get the turn started but stay loose. You might get halfway around if you're lucky.
Now, imagine that your are twirling a pencil. Does one part of it turn faster than the rest of it? No. It moves as one. Ideally, this is how your body should turn as well. Of course, you may have to give yourself a little leeway to get the turn started, but you should quickly pull into a tight body alignment. Try the pirouette again on the floor, this time squeezing your legs, hips, stomach and back muscles. You should be able to turn somewhat faster and farther.
The next element is something that may be a little trickier to visualize. From physics, there is a property called the conservation of angular momentum, which says that an object of constant mass will spin faster when the radius is smaller. Now, this doesn't mean that your body has to be as thin as a rod, but rather, focusing your center of gravity to minimize the radial distance.
Figure skaters know this property well. When they spin, they spin faster when they pull their arms closer and tighter to their body. Unfortunately, gymnasts don't always have the luxury of pulling their arms closer to their bodies when they turn, but when it is applicable, it can be very useful. In tricks such as jump full turns or layout twists, it can make quite a difference.
When your arms are hanging out away from your body as you twist, you are essentially increasing the radius of mass that has to rotate around the axis. Your center of gravity moves to somewhere in front of your body, increasing the radius of the circle, thus making rotation slower. If the trick you are doing allows it, you can pull the center of gravity closer, shortening the radius, you should notice you'd have an easier time turning.
Besides moving your arms, you can move your center of gravity closer by standing more vertically, especially when applying this to pirouettes. When you lean forwards or backwards in a pirouette, your center of gravity is somehwere outside the axis of revolution. Not only will this slow your pirouette, but it will throw you way off balance as well.
So, to summarize, there are two things you can do
to make twisting a more efficient movement. You can:
1) squeeze your body so that your body turns as a whole, helping you to conserve your momentum into the turn
2) decrease the radius of the circle in which your body twists
Experiment a little so you can recognize what works and what doesn't. Getting your body to do it is the best way to learn. Good luck!