The shoulder joint is designed to allow the most range of motion of any joint in the human body. Generally, this is more than enough motion to accomplish daily tasks and to manipulate our environment. Individuals that participate in throwing sports, particularly volleyball, tennis, and baseball, test the limits of range of motion and muscle control. In honor of VTPT’s recent visit to Centennial Stadium to see the Lake Monsters, let’s break down an overhead throw in baseball.
As this diagram illustrates, the late cocking and follow-through phases place the shoulder joint in the most extreme positions. The late cocking phase is vital for creating speed on a throw, but it places the shoulder in extreme external rotation and forces the humerus forward in the joint. As the throw progresses through acceleration the shoulder rotates inward rapidly. During follow through, the muscles on the back of the shoulder have to work very hard to slow the shoulder down. Over time, these extreme movements stretch the muscles and ligaments surrounding the shoulder, decreasing the overall stability of the shoulder joint. Shoulder and elbow injuries are extremely common in the throwing athlete. If you have ever watched or participated in these sports, the following conditions are probably familiar. A rotator cuff tendonitis or tear occurs when the muscles in the back of the shoulder are gradually frayed over time, causing pain that radiates down the arm during activity. Other muscle groups that are susceptible to tendonitis include the biceps in the front of the shoulder and the elbow flexors on the inside of the elbow. SLAP lesions are tears that occur in the upper part of the labrum, which is connective tissue that lines the joint, resulting in a catching or locking sensation in the affected joint. The elbow and the nerves around it are also susceptible. The ulnar nerve is stretched when the elbow is bent and can become inflamed under repeated strain, causing numbness and tingling in the ring and little fingers.
Whether you are a pro-player or play on your company’s softball team every summer, there are some very simple things that you can do to keep your throwing arm in shape. Part of this is paying attention to any arm pain that develops while you play and seeking medical advice if it persists for more than 48 hours. Good form comes from a combination of upper back, shoulder, and core strength. These exercises hit the major groups involved:
Additionally, you could consider blowing up a balloon. That’s right – try an exercise that involves blowing up a balloon like the one provided here to engage your diaphragm. The diaphragm acts as a respiratory muscle, but it also supports the back and influences rib cage movements. The position of the rib cage has an enormous impact on shoulder range of motion. Check out this recent article from USA Today to hear how Bronson Arroyo of the Arizona Diamondbacks is using his balloon to keep himself in the game.