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Smart Stuff About Body Rotation...

Friday, 11 March 2016 00:10

By Gary Hall Sr. (ustriathlon.org)

All of the elite swimmers of the world rotate their bodies along the long axis, the axis that their body is moving down the pool, while swimming freestyle and backstroke. They don’t just rotate a little bit. They rotate a lot. The question is, why?

It is commonly believed by both coaches and swimmers that the reason for rotating the body is to reduce frontal drag; that the body has a lower drag coefficient on its side than it does on its stomach. Although I am all for reducing frontal drag, I...

do not believe that this is the reason that we rotate. I do not believe that the drag coefficient of the human body is significantly different in the water on its side than it is on its stomach. If it were, we would be kicking faster times on our sides … but we don’t.

The truth is that it takes a lot of core strength and work to rotate our bodies from one side to the other while moving down the pool. So if it is not to reduce drag, why then? I believe there are two compelling reasons why we rotate our bodies on these two strokes. The first reason is a biomechanical one and the second is related to laws of motion or propulsion.

If I were to pin your shoulders to the wall in the gym and bring the pulley machine over, you could pull a certain amount of weight downward, using essentially the same pulling motion as you would in the water. If I unpinned your shoulders and allowed you to rotate your body inward toward the pulley machine and you duplicated that same pulling motion with the same elbow bend, I can guarantee that you will be able to pull more weight downward. The reason is that when you rotate in, your big back muscles, particularly the latissimus dorsi muscle, gets into the act. When your shoulders were pinned, that big muscle was sitting on the sidelines, unable to offer much help. By rotating our bodies in the water, we gain a biomechanical advantage of power on the pull. READ MORE