One hears the word shoulder rehabilitation and testing for athletes involved in throwing. This is also true for athletes involved in hitting an object with an instrument such as a racket. In the presence of dysfunction and pain in the shoulder isolated tests and exercises are commonly performed. This can be very helpful, however in order to treat for dysfunction and enhance performance in throwing one has to understand the contributing factors to the speed of the ball. In order to do so the entire kinematic chain has to be analyzed. Therefore to treat and train for throwing performance one has to be an expert on the entire kinematic chain.
The importance of the integrated kinematic chain in throwing can be exemplified by throwing in water compared to that of on the ground. Throwing in water polo is very different than handball. The speed of the throw in water polo is slower than that in handball, and we have to ask ourselves why is this. The ground certainly has something to do with this. As we are performing the throw, different joints from the ground to the hand will contribute rotational energy that ultimately leads to the speed of the ball.
Toyoshima and colleagues performed a simple analysis of segmental contribution to throwing in 1974. They imposed restriction of movement of different segments in the body while throwing. As motion in the lower extremity and trunk was restricted speed of the ball decreased by 60% when throwing. Then one might say that this is obvious, and it is. However, the obvious is not implemented in testing, rehabilitation and training of the shoulder. No wonder we end up with dysfunctional shoulders.
Jessica, Ali and Ola