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.
