The Thoracic Outlet Syndrome - Part Two Posted By : Jonathan Blood-Smyth

Physiotherapy examination starts with the therapist assessing the posture of the patient, often before they have taken any of their clothes off. A rounded or slumped shoulder posture and a poking forward neck and head stretch the neck and shoulder blade muscles and may make this syndrome more likely to occur. Active range of movements of the neck will be examined and any restrictions noted. The neck may be placed in combined positions involving two or more pure movements plus downward pressure in an attempt to bring on symptoms. Range of motion of the shoulders is also assessed.



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.



Presentation of the neurogenic form of thoracic outlet syndrome is indicated by the small muscles of the hand showing weakness and perhaps wasting. The ulnar nerve supplies the feeling to part of the hand and this can be involved as it gets its nerve supply again from the lower parts of the brachial plexus. In the last type of thoracic outlet syndrome, the non-specific type, the large number of patients present with less well defined pain symptoms in the whole arm and with unclear and equivocal examination findings.



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.



Mechanical or traumatic stresses applied to the neck and shoulder region can contribute to thoracic outlet syndrome, perhaps combining with an already abnormal anatomy such as a cervical rib. Acute cases of this syndrome secondary to vascular occlusion need speedy diagnosis and surgical intervention to release the compression and perhaps repair any damage to the vascular structure. Conservative treatment consists of physiotherapy, anti-inflammatory medication and other pain treating modalities such as transcutaneous electrical nerve stimulation (TENS).



Conservative management is useful in a large group of patients and if the pain does not settle over a considerable period then surgery remains an option. Physiotherapy assessment includes any abnormalities of posture and imbalances in muscles around the shoulder and neck region. The maintenance of static postures for considerable times or repeated return to certain postures may provoke abnormal neck function.



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.

Jonathan Blood Smyth, editor of the Physiotherapy Site, writes articles about Physiotherapy, back pain, orthopaedic conditions, neck pain, injury management and physiotherapists in halifax. Jonathan is a superintendant physiotherapist at an NHS hospital in the South-West of the UK.