The elbow is the joint where the upper arm bone, known as the humerus, meets the two bones of the lower arm, known as the ulna and radius. A combination of hinge and pivot joints, the hinge allows the arm to bend like a door while the pivot lets the lower arm twist and rotate. The anatomy of the elbow is integral to the function of a baseball pitch. Damage to this region of the body will harm or encumber proper performance. Treatments include rest, ice and, if serious enough, surgery and rehabilitation.
Pitching
The acceleration phase of a pitch, when the arm is thrust forward, is typically the phase that causes the greatest amount of damage. At this time the wrist is slightly extended, stretching the flexor muscles of the forearm. This puts a strain on the ligament of the elbow. The wrist then transitions to a flexed position, causing a forceful contraction of the forearm flexors. When these muscles are stretched, tension develops in the tendons. It is at this point that damage and pain can occur, especially from overuse of the arm. Improper pitching technique places an even greater workload on the structure of the elbow.
Pitcher's Elbow
Medial epicondylitis, known as pitcher's elbow, is a pain on the inside of the elbow caused by repetitive throwing. If left untreated, elbow swelling and a serious decrease of performance may develop. This condition is caused by microtears that appear as a result of the strain placed on the structure of the elbow by high-velocity pitches.
Little Leaguer's Elbow
A common problem of the elbow in children is known as medial apophysitis, also known as Little Leaguer's elbow. This injury occurs when repetitive throwing creates a strong pull on the tendons and ligaments. In the short term, it is an aggravating reservoir of pain on the inside of the elbow; but in the long term the tendons and ligaments may tear away from the bone completely. The tearing can pull bone fragments along with it, which will disrupt normal bone growth and lead to deformations.
OCD
Osteochondritis dissecans, or OCD for short, is a name given to a condition that is also caused by excessive throwing. It develops when the pull that occurs on one side of the elbow pushes on the opposite side. The elbow is then compressed. In children the compressed joint can actually smash immature bones together. This action can loosen or fragment bone and cartilage. It is a source of pain on the outside of the elbow, and causes a restricted range of movement and a locking of the joint.
