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.
Examination of the nerves and the blood supply to the arm will normally be performed, with the greatest effects on the nerves and muscles supplied by the lower roots of the brachial plexus. If the veins are being compressed in the vascular type of syndrome then patients turn up with swelling and blueness of the arm. If the arteries are the vessels suffering compression then the arm can be pale, cool and without a pulse or with a very weak one. The blood pressure in the affected arm may be reduced by more than 20mmHg compared to the normal arm.
The neurogenic type of thoracic outlet syndrome presents with wasting and weakness of the hand’s small muscle groups, usually involving the thumb. With a reduction in the feeling of the hand supplied by the ulnar nerve this again points to the involvement of the lower group of brachial plexus nerves. The third described group exhibiting the typical symptoms is the non-specific thoracic outlet group, by far the largest, with a more diffuse described pain and examination findings which can be unreliable and hard to pin down.
Thoracic outlet syndrome can be brought on by a large number of neck and shoulder anatomical structures and this is reflected in the numbers of diagnostic tests which have been developed to investigate this problem. A significant problem with these tests is the occurrence of false positive and false negative tests. False negatives mean that the test shows the problem not to be present when it really is and false positives mean the test indicates the tested problem to be present when in reality it is not.
Physiotherapists can perform Roos stress test, whereby the patient is asked to maintain their arms in a position of “hands up” while they close and open their hands repetitively. The test is positive if it brings on the usual symptoms complained of or if the arms feel tired and heavy. The structures which cause thoracic outlet syndrome can be of bony or soft tissue origin. The compression or obstructive problems can be caused by a bony structure such as a neck rib or a bony growth on the clavicle or ribs. Soft tissue compressive forces can be due to a fibrous band or oversize muscles.
The neck may be more likely to develop thoracic outlet syndrome if it suffers some trauma or mechanical stresses which can combine with any anatomical abnormality such as a cervical rib. If the blood vessels are obstructed then this acute syndrome threatens the health of the arm and surgical release of the compression and blood vessel repair should be urgently considered. The remainder of treatment is conservative including TENS (transcutaneous electrical nerve stimulation), anti-inflammatories and physiotherapy assessment and intervention to the neck and shoulder.
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.
Chronic compression may be caused by the postural abnormality increasing the local compression or tension forces on the nerves. If muscles are kept in shortened positions for lengthy periods they may adopt that new length and when stretched, react with pain. Muscle imbalance can occur with some muscles typically lengthened and thereby weakened and others shortened and thereby strengthened. This leads to an abnormal balance of muscular strength and length, generating abnormal forces in the neck region. Education is a significant matter in the treatment of these patients in an effort to change their posture.