Overuse injuries of the upper extremity in the competitive athlete: magnetic resonance imaging findings associated with repetitive trauma.

Overuse injuries are a very common cause of pain in athletes, accounting for a significant loss of training time and missed competitions. Magnetic resonance imaging (MRI) is playing an increasing role in facilitating the expeditious and safe return of these individuals to their preinjury level of physical performance by allowing accurate diagnosis. Sports physicians are increasingly relying on the exquisite anatomic detail afforded by this technique to formulate diagnoses that assist with the optimal management of these athletic injuries. Some upper extremity overuse entities are well recognized; two examples are medial epicondylitis, classically appearing in baseball pitchers, and lateral epicondylitis, in tennis players. Other less well-known injuries of the upper extremity, such as intersection syndrome in rowers and distal clavicular stress fractures in weightlifters, are frequent occurrences in certain circles of athletes. The following article is a pictorial review of the MRI findings of upper extremity overuse injuries encountered in the competitive athlete, with an emphasis on the sports scenarios in which they occur. We will depict mechanisms of injury and applicable anatomy and show characteristic imaging findings. A wide range of entities are addressed, including but not limited to overuse injuries occurring in baseball, swimming, gymnastics, weightlifting, bowling, and cycling.