Thoracic outlet syndrome

Thoracic outlet syndrome involves the compression of nerves and arteries as they pass between the anterior and middle scalene muscles in the neck.

The symptoms:

Thoracic outlet syndrome affects the nerves and the arteries passing into the hands and arms. If the compression is affecting the nervous system, then symptoms can include pain, numbness and tingling fingers, pain in the neck and shoulders, aching arms and hands or a weak grip.

If the compression is affecting the circulatory system, then you could see a discoloration of the hands or arms, a weak pulse or arm pain and swelling. These symptoms are caused by decreased blood flow into the arms through the subclavian vein and artery.

So what is going on?

The neck consists of seven vertebrae stacked one on top of the other. Small openings between the vertebrae allow for nerves to exit the spinal cord and into the body, in this case the arms. As the nerves leave the spinal cord, they form a web-like interchange, rather like criss crossing highways complete with exit ramps, called the brachial plexus. Two muscles extend down from the neck and attach to the first rib underneath the collar bone. These muscles, the anterior and middle scalenes, pass either side of the brachial plexus. The image shows the proximity of the scalene muscles to the brachial plexus and blood vessels

What causes it?

Muscles can become stressed and tense from continuous punishment. An example of this could be stress caused by a high paced desk job, where the person slumps into bad posture as the day goes by. It could also be caused by repetitive lifting of the arms and over-use of the wrists and arms, such as swimmers, rock climbers or weightlifters. It could also come about through trauma, such as a car accident causing damage to the clavicle.

What can be done?

The scalene muscles can be released using pressure techniques to the muscles in the neck. Often times, there will be a trigger point, a hard muscular knot, just under the clavicle, at the base of the front of the neck. This can be released using pressure into the trigger point until the point looses sensitivity. Mobilisation techniques can be used to restore movement to the neck, freeing the neck and allowing you to turn the head further than previously allowed. There may be cases where thoracic outlet syndrome is not caused by muscular tension. This may require surgery to alleviate.