As a certified hand therapist, I often treat people suffering from the symptoms of carpal tunnel syndrome (CTS).  Carpal tunnel syndrome is the compression of the median nerve (one of the three main peripheral nerves that provide power and sensation to the arm and hand) as it passes through a small tunnel created by the 8 small wrist bones and a broad, thick ligament that attaches from one side of the bones to the other.  A less commonly known injury, but one that I am seeing with more frequency, is called Radial Tunnel Syndrome (RTS).   If you are experiencing an aching or burning sensation in the back of the forearm or over the back of the wrist, you may have symptoms of RTS rather than CTS.

Anatomy

The radial nerve is one of three main peripheral nerves that provide sensation and power to the arm and hand (the other two are the median nerve and the ulnar nerve).  The radial nerve begins at the cervical spine.  The nerve then passes through the thoracic outlet, spirals around the humerus (the upper arm bone), over the back of the elbow and into the back side of the forearm.  In the forearm, close to the elbow, it passes through the supinator muscle, the muscle that turns the palm up (such as when using a screwdriver).

The radial nerve is responsible for providing sensation to the back side of the forearm and the hand.  It is also responsible for providing power to the muscles that pull the wrist back and straighten the fingers at the large knuckle joint.

Causes of Radial Tunnel Syndrome

The radial nerve passes through an anatomical tunnel on the outside edge of the forearm just below the elbow comprised of muscle, tendon and ligamentous tissue.  Repetitive or forceful movements can cause friction at several sites along the nerve pathway.  It can also cause swelling in the tissues that surround the nerve.  This causes the nerve to be compressed or pinched leading to sensations of aching, burning or numbness and tingling.

Symptoms of Radial Tunnel Syndrome

Symptoms of RTS include an aching or burning pain over the back side of the forearm and/or into the back of the wrist.  There may be tenderness over the back of the elbow and forearm close to the elbow.  Pain may be worse with activities that require a lot of wrist movement (such as manipulating the mouse), finger movement (such as clicking the mouse), and palm up movements (such as using a screwdriver).  With pressure against the tender area close to the elbow, you may experience a tingling or radiating pain.  The arm may rapidly become tired and feel heavy.

Things to Help Prevent and Control Pain from RTS

If you are experiencing symptoms of RTS, here are a few things you might try to help you reverse the symptoms.

1. Rest from the activity that is causing the problem. 
   
   1. A vertical mouse that places the forearm in a neutral position (the “handshake” position) may be helpful. 
      
   2. Do not swivel the mouse with wrist movement.  Keep the wrist neutral (straight and level, not bent forward or back or angled to either side) when typing and using the mouse. 
      
   3. Control the mouse by using the larger shoulder and elbow muscles to move it. 
      
   4. Keep the fingers relaxed on the keyboard and mouse. 
      
   5. Don’t forcefully straighten or lift the fingers while typing or clicking. 
      
   6. Use the least amount of pressure necessary to activate the keyboard and control the mouse. 
      
   7. Use a wrist brace to help keep the muscles of the forearm relaxed. 
      
   8. Take micro-breaks.
2. Use cold packs and hot packs.  A cold pack placed over the forearm muscles several times a day can help control swelling from overuse.  Hot packs can help improve flexibility.  Both can help control pain. 
   
3. Stretch the forearm muscles.
   
4. Avoid heavy lift, grip or twisting activities.
   
   1. Using a screwdriver
      
   2. Picking up luggage
      
   3. Weight-lifting.
5. Be careful of using tennis elbow straps that can place additional pressure on the radial nerve.
   
6. Seek medical attention if symptoms do not rapidly improve.

RTS is often confused with tennis elbow.  Tennis elbow is an inflammation of the tendons as they attach on to the lateral epicondyle (a prominent bony protrusion on the outside edge of the elbow).  The tenderness associated with RTS is often a few inches farther down the forearm, more on the muscle than on the bone of the elbow.  A tendinitis pain is often sharper with activity and, unless it is a severe case, lessens with rest.  Nerve pain, such as with RTS, can be more of an aching, burning pain that may become more severe after activity or at night.  When seeking medical attention, be specific with your description of symptoms so that you can help your doctor diagnose the problem accurately.
Marji Hajic is an Occupational Therapist and a Certified Hand Therapist practicing at the Hand Therapy & Occupational Fitness Center in Santa Barbara, California. For more information on hand and upper extremity injuries, prevention and recovery, visit Hand Health Resources
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