What Is Claw Hand Deformity?

Medically Reviewed by Dan Brennan, MD on October 25, 2021
3 min read

Claw hand deformity is a condition where your fingers are bent into a position that looks like a claw. It may affect all of your fingers or only some of them. The cause is usually related to damage to a major nerve that starts at the neck and controls the muscles in your hand and arm. 

Claw hand deformity brings on a loss of feeling and function. You may lose touch sensation, and your ability to move the hand can become limited. 

Some people are born with one or both hands affected. Other people get the condition due to illness or injury.

The root cause is damage to the ulnar nerve. This nerve travels from your neck all the way to your pinky finger. The ulnar nerve tingles when you bump your arm and get the sensation called "hitting my funny bone".

The ulnar nerve affects all the muscles in your shoulder, arm, and hand. Damage to it can cause problems with your hand like claw hand. You’ll need medical care for any problems related to the nerve.

An injury to the ulnar nerve anywhere along its length can cause nerve palsy. This is a combination of paralysis and loss of feeling. Disabling the ulnar nerve has harmful effects on your hand. Not only do you lose sensation, but the muscles may also respond by tightening up and pulling the fingers into a permanently curved position.

People can be born with a claw hand. This is called a congenital condition. Doctors usually diagnose it shortly after birth.

Claw hand can develop later in life due to injuries or certain illnesses. Injury is the most common cause of claw hand deformity. Nerve damage can happen due to a traumatic injury or from repetitive motion injuries as well.

You can damage your ulnar nerve in a variety of ways, including:

  • Putting pressure on the elbow or base of the palm over a long period
  • Breaking or dislocating your elbow
  • Repeated motion injury from frequent elbow bending
  • An injury to the arm causes swelling that presses on the ulnar nerve

There is also a condition called ulnar nerve entrapment. Your nerve shifts out of place or becomes pinched in this condition. This can happen at the elbow or the wrist. You may notice discomfort in your hand if your ulnar nerve is injured, such as:

  • Unusual sensations in your little finger and ring finger
  • Weakness and loss of coordination in your fingers
  • Pain, numbness, and less feeling in your hand and arm
  • Tingling or burning sensation along the length of the ulnar nerve

Not all ulnar nerve injuries develop into claw hand deformity. But even minor irritation or damage to the ulnar nerve can affect how well your hand works and cause discomfort. 

You should talk to a doctor if you have any of the symptoms of ulnar nerve neuropathy.  They may recommend treatment such as a splint or physical therapy. These measures can repair the existing damage and keep the condition from getting worse.

You may be able to improve hand function with rehabilitation in some cases where your nerve damage is mild to moderate. Your doctor and a trained hand therapist will work with you on a plan to bring back as much function as possible. You’ll need to commit to the hard work since it often takes a lot of therapy. But you may never fully regain use of your hand.

Some people can have hand surgery to try and repair the damage. One type of surgery for claw hand deformity is a tendon transfer. This is an operation where doctors replace the non-working muscles and tendons with muscles and tendons from another part of your hand.

Tendon transfer surgery may help your condition, but there can be complications. All surgery comes with a risk of infection. Tendon transfers also aren't always 100% successful. The transferred tendon may need another surgery to attach it more securely. You may only regain partial use of your hand.‌ Before you get any surgery, ask your doctor to explain all the possible benefits and risks. Also find out what you need to do to have the best recovery possible.