What is Carpal Tunnel Syndrome?
Carpal Tunnel Syndrome – Google the term and you will get over 600,000 hits. Pick up a magazine or newspaper and there is a chance that you will find some mention of carpal tunnel syndrome. Wear a brace or cast out in public and everyone will ask if you have carpal tunnel syndrome. The term has become a commonplace part of our language. There is even a band that goes by the name of Carpal Tunnel Syndrome.
However, the term carpal tunnel syndrome has become erroneously associated with all hand pain. The truth is that many other types of injuries can cause hand pain. In order to recover completely from repetitive strain pain, it is important to determine the true cause of the pain and not just treat the symptoms. It is important that we not assume and treat all hand pain as if it were carpal tunnel syndrome.
So, what exactly is carpal tunnel syndrome and how will you know if you have it?
Carpal tunnel syndrome is the compression of the median nerve at the wrist.
The nerves to the hands are long “threads” that start at the neck, branch under the arm pit, and travel down to the fingers. The nerves are the power cords that provide the muscles along their pathway with power and provide certain areas of the skin with sensation. They also assist with circulation and provide the skin with the ability to sweat.
The carpal bones are the eight small wrist bones that connect the hand to the forearm. They are arranged, for the most part, in two rows of four bones each. The arrangement of bones is slightly curved like a “C”. A strong, thick, wide ligament, the transverse carpal ligament, attaches from one end of the carpal bones to the other. The bones and the ligament over it create the carpal tunnel.
The median nerve passes through this tunnel on the way to the hand. Nine tendons also pass through the tunnel along with the nerve.
Tendons are the rope-like end of the muscles that attach muscle to bone. When the muscle contracts, the rope-like end of the muscle (the tendon) pulls on the bone and creates movement. The tendons that pass through the carpal tunnel are the eight tendons that bend each of the two finger joints plus the tendon that bends the thumb tip. These muscles begin at the inside edge of the elbow.
The nerve is the most vulnerable structure in the carpal tunnel. If there is any swelling of the tendons related to over-use, repetition, poor wrist positioning or any other cause, the nerve gets pinched and the nerve impulses do not travel along the nerve pathway properly. This can affect muscle power, sensation, and circulation.
The median nerve is responsible for sensation to the thumb, index, middle, and part of the ring finger. The median nerve is also responsible for the strength to the thick wad of muscles at the base of the thumb.
So the symptoms of a true carpal tunnel syndrome will be numbness or tingling in the thumb, index, middle and ring finger as well as loss of thumb strength and coordination. The fingers may be painful, the muscles at the base of the thumb may hurt, and sometimes people feel as if they have a tight band around their wrist. Pain may travel along the forearm muscles towards the elbow and the forearm muscles may become taut. People say that they often feel as if they are clumsy and they may report that they drop items frequently. They may also feel as if their fingers are slightly swollen. In advanced cases, the muscles at the base of the thumb may become wasted and flatten. Pain may radiate all the way up the arm into the shoulder and neck.
If you have these symptoms, a visit with a physician can help determine if carpal tunnel syndrome is truly the cause. Sometimes, if the same nerve is pinched higher along in the pathway, other causes can mimic carpal tunnel. Certain tests, along with your description of the symptoms, can help the doctor make a definitive diagnosis.
Check out these articles for additional information and for tips on preventing carpal tunnel syndrome.
Carpal Tunnel Syndrome - Back to the Basics
Carpal Tunnel Syndrome ABCs
Marji Hajic is an Occupational Therapist and a Certified Hand Therapist practicing in Santa Barbara, California. For more information on hand and upper extremity injuries, prevention and recovery, visit Hand Health Resources.