Thoracic Outlet Syndrome Management - Part Two
The physiotherapist will typically begin the examination even before the patient takes off any of their clothes by observing the usual posture they tend to adopt. Posture of the shoulders may be slumped and rounded, forcing a stretch from the neck and shoulder blade muscles which might add to the possibility of this syndrome occurring. The physiotherapist will examine the neck''s ability to reach full range of motion and may increase the testing stresses by compressing the neck whilst it is in a combination of movements. This can bring on the symptoms if normal testing does not.
The vascular and nervous supply to the arm will typically be examined, with particular attention to the muscles and nerves of the lower parts of the brachial plexus, which are most commonly involved. Compression of the venous system can result in the affected arm being swollen and bluer in colour while if the arterial part of the vascular system is compressed the results are different. In this case the arm can be without pulses, cool, and suffer a loss in blood pressure compared to the normal arm of twenty mmHg or more.
In the case of thoracic outlet syndrome due to neurological compression the finding are often of weakness and wasting of the small muscles of the hand. There may also be reduced sensation in the areas supplied by the ulnar nerve, which again reflects the fact that the lower nerves of the brachial plexus are most often involved. The last type of this syndrome, that of non-specific thoracic outlet syndrome, has widespread but less precisely located pain, with less precise and clear examination findings, making the diagnosis unreliable at best.
The large number and type of anatomical structures potentially contributing to thoracic outlet syndrome has meant that there is a large number of tests to provoke the symptoms of the typical syndrome. Unfortunately these tests result in high numbers of results which are false-negative and false positive. False-negative results mean that the tests did not show any evidence for the syndrome but it is present anyhow, and false-positives mean that the test shows the presence of the syndrome when in reality it is not present.
Roos stress test is a typical test for thoracic outlet syndrome, the patient is instructed to maintain their arms in a "hands up" posture whilst opening and closing their hands repeatedly. A positive test result occurs if the arms feels tired or heavy or it elicits the typical symptoms. Thoracic outlet syndrome can be caused either by soft tissue or bony anatomical structures. Obstruction or compression can occur from bony parts such as a growth on the collar bone or ribs or with the presence of cervical ribs. Soft tissue abnormalities include tight fibrous bands or overdeveloped muscles in athletes.
Trauma to the neck and mechanical stressors may combine with any abnormalities in neck anatomy such as cervical ribs to increase the likelihood of developing thoracic outlet syndrome. Obstruction of the blood supply is an emergency and should be speedily assessed and surgically decompressed with repair to the arteries or veins. Most people with this syndrome are however treated conservatively with anti-inflammatory drugs, transcutaneous electrical nerve stimulation (TENS) and assessment and mobilisation or exercise prescription by a physiotherapist.
An increase in the local compressive or tension forces can be produced by postural abnormality, causing the nerves to suffer chronic compression. Keeping of muscles in a shortened posture changes their normal length, makes them weaker and means they react with pain when stretched. Muscles can also become lengthened and weakened by being chronically stretched, and along with shortened muscles this forms the idea of muscle imbalance producing symptoms. The longer term changes in posture which are required to make an improvement in this syndrome mean that patient education is a priority.