Repetitive use of the elbow can cause cubital tunnel syndrome.
Symptoms include numbness and a pins-and-needles sensation of the ring and little fingers and pain in the elbow.
Doctors base the diagnosis on an examination and, if needed, the results of nerve function tests.
Treatment includes physical therapy and a splint, or sometimes surgery.
(See also Overview of Hand Disorders Overview of Hand Disorders Hand and finger disorders include ganglia, deformities, disorders related to nerves or blood vessels, osteoarthritis, trigger finger, Kienböck disease, and infections. Some other disorders that... read more 
.)
The cubital tunnel is called a tunnel because it is the narrow passageway through which the ulnar nerve passes around the elbow on its way to the wrist and hand. The ulnar nerve provides sensation to the little finger, ring finger, and the side of the hand. Because the ulnar nerve passes close to the surface of the skin at the elbow (“funny bone”), it is easily damaged by repeatedly leaning on the elbow, by bending the elbow for prolonged periods, or sometimes by abnormal bone growth in the area.
Cubital tunnel syndrome is less common than carpal tunnel syndrome Carpal Tunnel Syndrome Carpal tunnel syndrome is a painful compression (pinching) of the median nerve as it passes through the carpal tunnel in the wrist. The cause of most cases of carpal tunnel syndrome is unknown... read more 
. Baseball pitchers are prone to cubital tunnel syndrome because of the extra twist of the arm required to throw a pitch called a slider.
Symptoms of Cubital Tunnel Syndrome
Symptoms of cubital tunnel syndrome include numbness and a pins-and-needles sensation of the ring and little fingers and pain in the elbow. Eventually, weakness of the hand, particularly of the ring and little fingers, may develop. Weakness may also interfere with the ability to pinch using the thumb and index finger and the ability to grip with the hand because most of the small muscles in the hand are controlled by the ulnar nerve.
Severe, chronic cubital tunnel syndrome can lead to muscle wasting (atrophy) and a clawlike deformity of the hand.
Diagnosis of Cubital Tunnel Syndrome
A doctor's examination
Sometimes nerve conduction studies
Sometimes imaging tests
Doctors often base the diagnosis of cubital tunnel syndrome on an examination. However, nerve conduction studies Nerve conduction studies Diagnostic procedures may be needed to confirm a diagnosis suggested by the medical history and neurologic examination. Electroencephalography (EEG) is a simple, painless procedure in which... read more 
or advanced imaging tests, such as magnetic resonance imaging Computed tomography (CT) and magnetic resonance imaging (MRI) A doctor can often diagnose a musculoskeletal disorder based on the history and the results of a physical examination. Laboratory tests, imaging tests, or other diagnostic procedures are sometimes... read more 
(MRI) or ultrasound, may be needed to help pinpoint the exact area of nerve damage, especially if surgery is being considered.
Treatment of Cubital Tunnel Syndrome
A splint and physical therapy
Sometimes surgery
People with mild cases of cubital tunnel syndrome undergo physical therapy, wear a splint at night to avoid overbending the elbow, and avoid pressure over the elbow. An elbow pad worn during the day can be helpful.
Most people who do not respond to splinting or who have more severe cases of nerve compression may benefit from surgery, which usually consists of releasing pressure on the nerve.
