A flexor pronator strain is a common elbow injury in baseball pitchers. It is a strain or tear of the origin of the flexor-pronator muscles off the medial epicondyle, or the bony prominence many know as “the funny bone.” These muscles flex the wrist and pronate the forearm, or turn the palm toward the floor.

Signs and symptoms of a flexor pronator strain

A flexor pronator strain can either result from an acute event or can develop as a result of overuse. You might remember a specific throw where you felt sharp pain on the medial side of your elbow. Or you might not remember a specific injury but notice pain there that gets worse with continued pitching. Your pain will usually be located just below the bony prominence on the inside of your elbow. You might have pain flexing your wrist or pronating your forearm.


If you see an orthopedic surgeon or sports medicine physician, he will likely order an x-ray, even though it is usually unremarkable. An MRI can show a strain or tear of the tendon as well as rule out an injury to the ulnar collateral ligament, also known as the Tommy John injury.

Pitching and throwing can cause a flexor pronator strain

Treatment of a flexor pronator injury

Usually a flexor pronator strain resolves with rest from pitching to give the tendons time to heal. Ice and physical therapy can also be helpful to decrease the athlete’s symptoms. As the pain improves, the pitcher will be started on a long toss program prior to returning to full pitching. Occasionally a complete tear of this tendon could require surgery.

If you have suffered a flexor pronator strain, watch the video to learn more about this elbow injury, the symptoms, diagnosis, treatment and return to pitching.

Also read:
Treatment of a flexor-pronator injury
Flexor-pronator strain

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