I believe that thoracic mobility is key for good shoulder rotation. The speed of the rotation and ability to strike adds power to the underwater stroke and at the same times helps the recovery arm with elbow above the shoulder.
Is there an optimum amt of rotation for swimmers or is the standard 45 degree shoulder rotation a general rule of thumb?
I would imagine as long as integrity of core is maintained more rotation can give more power? If so, does the distance of the race matter.
Please let me know if I am on track or am mistaken!
We find that it is not generally recognized nor understood how important the body rotation is in generating propulsion (power). The body rotation should be separated into two different components, shoulder and hip, as the two occur at different times (usually about . 2 seconds apart) and in different amounts. In fact, we classify freestyle technique according to where more effort is being placed, shoulder or hip.
45 degrees is a typical maximal angle of upper arm and water surface for many swimmers….just not the elite ones. We find that most of them rotate more, some close to 90 degrees. By doing so, they will generate more kinetic energy from the shoulder rotation than a swimmer who rotates to only 45 degrees.
Rotating that far requires more work and fitness, so must be practiced constantly. The speed of the hand entry is also tied to the speed (angular velocity) of the shoulder rotation…so that must also be emphasized.