As with most sport injuries, those occurring to the elbow and the surrounding structure are either caused by a sudden trauma or force directed into the joint, or by the impairment of overuse. The elbow is not subjected to the same physical stresses as those commonly experienced by an athlete to the ankle or the knee, but an elbow injury can be as debilitating as any other, given the elbow's prominence in the mechanics of throwing, lifting, and propulsion in many sports.
The elbow joint is created by the confluence of three bones: the humerus, the radius, and the ulna. The three bones are joined into a functioning joint by the ligaments that connect the bones to one another and by the tendons that join both the upper and lower arm muscles to the structure. The elbow joint is cushioned by bursa, the fluid-filled sacs of which the olecranon is the most prominent. The elbow also contains meniscus, or cartilage, that serve to cushion the bones of the elbow as they are rotated and extended through movements such as throwing.
The elbow has two characteristics that are responsible for its range of motion. The elbow can bend (flex) and completely straighten (extend) due to its hinge shape. The joint can also act as a ball and socket mechanism, as witnessed by the rotation of the hand to either a palm up or palm down position.
Acute injuries to the elbow are frequently caused by either a sudden fall, or by a blow absorbed by the structure. The athlete will fall without warning on an outstretched hand, which creates very heavy forces, most of which are not absorbed by the hand but, instead, radiate along the forearm to the elbow joint. As the elbow is often in a flexed positioned at the moment of impact, the applied forces will drive and rotate the elbow out of its socket, creating either a subluxation (partial dislocation) of the elbow, or a complete dislocation. The severity of the dislocation, coupled with the history of the particular person, will determine whether the dislocation will require surgical repair. Surgery will usually be required when there is a misalignment of the elbow bones.
A fracture of the end, or head, of the radial bone can occur through the same mechanics as does the dislocation of the elbow.
A serious elbow injury that arises with frequency in baseball is the tear of the ulnar cruciate ligament (UCL). This injury arises through the specific mechanics required to throw particular pitches in baseball, primarily the curve ball or pitches that direct twisting forces into the elbow. When a pitcher is required to throw a curve ball, the shoulder and then the elbow rotate as the pitcher delivers the ball with as much force as possible; the faster the ball is thrown, with the rotation imparted by the pitcher, the greater the likelihood of the ball achieving a greater degree of curve along its path. The significant forces of this pitch are not always well absorbed in the small UCL; over many repetitions, the UCL will become sprained, and ultimately fatigue into a full-sized tear. The UCL may also rupture in a single instance. UCL strains that debilitate younger pitchers are sometimes known as "Little Leaguer elbow."
A UCL tear will prevent the athlete from pitching; for many years it was perceived as a career-ending injury. In the 1970s, Dr. Frank Jobe of California pioneered a surgical procedure where tissue was grafted into the UCL, with considerable success. This surgery is now the accepted standard of elbow ligament reconstruction.
The overuse injuries that are sustained by athletes to their elbow joint are varied; all are often worsened by poor athletic technique, in conjunction with the repetitive stresses. Overuse injuries to the elbow include medial epicondilytis, lateral epicondilytis, and bursitis. Medial epicondilytis, or golfer's elbow, occurs to the inside of the elbow joint, a result of the repetitive overloading of the forearm muscles. Lateral epicondilytis, or tennis elbow occurs to the outside of the joint, as a result of overloading the outer forearm structure. Bursitis is an inflammation of bursa, fluid-filled sacs, particularly those located at the hinge of the joint. A sudden swelling of the elbow in this area may be evidence of a correspondingly sudden trauma to the bursa; a gradual or persistent swelling is common to a chronic injury. The bursa can become irritated through constant pressure being placed upon the exterior of the elbow joint, at the point of the hinge.
Most forms of overuse elbow injury can be treated through an application of the RICE method (Rest/Ice/Compression/Elevation), as well as the administration of over-the-counter pain medications. Bursa injuries may require the application of a corticosteroid, an anti-inflammatory agent. If the athlete is to engage in any form of sport where the injured elbow may incur physical contact, the joint will likely require protection in the form of a wrap or padded bandage.