The fingers and thumbs of the hand are controlled by the flexor muscles lying in the lower forearm. Long tendons connect the flexor muscles to the bones of the hands. The flexor tendons run along the palmar surface of the hand, close to the surface of the skin. As a consequence, they are highly susceptible to injury, and a variety of accidents may sever or tear these tendons. These types of injuries are especially common in rugby, football, wrestling, and rock climbing.
Symptoms of a flexor tendon injury include numbness on one or both sides of the finger, an inability to bend the joints of the finger, pain on bending the finger, tenderness along a finger on the palmar side of the hand, and mild joint swelling. You should see your doctor if you experience these symptoms. Ice and compression while waiting for medical attention can reduce blood flow to the injured area. Diagnosis of a flexor tendon injury will include a physical exam of the injured region, an assessment of the functioning of the affected area, and often an X-ray.
Treatment of these injuries requires surgical repair. Because the tendon has severed or torn, it will not grow back unless the torn ends are touching. Surgical repair should occur a soon after injury as possible to optimize recovery, which may take several months or more. You may experience some stiffness in the injured finger, and physical therapy will help your recovery.