The ulnar nerve is one of three main nerves that supply the upper extremity. It runs down the medial side (inside) of the arm, and is the nerve that is hit when you hit your “funny bone”. It provides innervation to several muscles of the forearm and hand. The nerve runs through a tunnel of tissue on the inside of the elbow known as the cubital tunnel, and it also runs close to the medial epicondyle, a bony prominence on the humerus bone.
The ulnar nerve can be compressed at many sites along its course, but is commonly compressed near the medial epicondyle when the elbow is repeatedly bent or kept bent for a long period of time. The ulnar nerve is commonly irritated in athletes who constantly throw, like baseball players and quarterbacks. It is also common in athletes who repetitively swing, like golfers and tennis players. External pressure on the nerve, like leaning an elbow on a desk over a long period of time, can also cause compression of the nerve.
Ulnar nerve compression presents with numbness and tingling that runs down the medial (inside) side of the forearm and hand. Characteristically, the pinky and half of the ring finger experience numbness and/or pain. Long term compression can lead to weakness and a loss of mobility in the affected forearm and hand.
Ulnar nerve compression can be treated with rest, anti-inflammatory medications (NSAIDS), physical therapy, and bracing to prevent the elbow from bending to avoid additional damage. If these non-surgical means fail to alleviate symptoms, surgery is recommended to relieve pressure from the ulnar nerve.