The ulnar nerve, one of the three main nerves in the arm, extends down the arm, across the elbow, and into the hand. When the nerve functions properly, it provides sensation to the pinky finger and half of the ring finger. It also controls most of the small muscles in the hand that help with fine motor movements, as well as some of the bigger muscles in the forearm that help to form a strong grip. You can actually feel this nerve as it passes behind the elbow and through a tight tunnel (the cubital tunnel) at the inside of the elbow.

When the nerve swells, usually due to an injury, it becomes trapped or compressed. The most common place where the nerve gets compressed is behind the elbow. Sometimes the compressed nerve is located at the wrist, beneath the collarbone, or as it comes out of the spinal cord in the neck. Although the problem usually originates in the elbow area, most symptoms occur in the hand and fingers because the ulnar nerve controls movement and sensation in this area.

Symptoms include:

  • Tenderness along the inside of the elbow
  • Tingling and numbness in little and ring fingers
  • Numbness in your hand when the elbow is bent, such as when you drive or hold a telephone
  • Difficulty with hand coordination
  • Decreased strength in the hand; muscle weakness
  • Pain along the inside border of the shoulder blade