Thoracic Outlet Syndrome


Thoracic Outlet Syndrome (TOS) is a condition affecting the shoulder, arm, and hand. Nerves and blood vessels supplying the arm and hand start at the side of the neck. Exiting from the side of the spine, they travel between two muscles (the scalene), over the top of the rib cage (thorax), under the collar bone (clavicle), through the arm pit (axilla) and down the arm to the hand. The area where the nerves and vessels leave the neck between the two scalene muscles and over the first rib is known as the Thoracic Outlet.


There are probably several causes of TOS. The common underlying cause of the syndrome is compression of the nerves and arteries of the arm in the Thoracic Outlet. Some people have an extra first rib or an old fracture of the clavicle, which limits the space for the vessels. A violent injury , such as a car wreck while wearing a shoulder harness, may also tear the scalene muscles. In the healing phases of this type injury, scar tissue may form in the healing muscle, leading to compression of the nerves and vessels. Compression can also occur with repetitive activities that require the arms to be held overhead or extended forward. The more likely cause is slouching forward and dropping the shoulders ; causing tension in the muscles at side of the neck and constricting the arteries and nerves.


Symptoms of TOS include pain, weakness, numbness and tingling, swelling, fatigue or coldness in the arm and hand. This syndrome can be very difficult to diagnose. The symptoms can mimic many other conditions, such as a herniated disk in the neck, carpal tunnel syndrome, and even bursitis of the shoulder.


Diagnosis of TOS can be difficult and frustrating. The history and physical examination can be suggestive of TOS, but frequently the symptoms are vague and difficult to track down. A chest xray may show an extra cervical rib, and be helpful in the diagnosis.

Electrical testsof the arm and special tests to check whether or not the blood vessels that run with the nerve may be required to confirm the diagnosis. Many times all of these test are negative and the symptoms and examination must be relied on to make the diagnosis.


Symptoms caused by variations in the bones and muscles may not respond to physical therapies; however, good posture and overall conditioning are very important in treating all causes of TOS. Attention should be paid to the length of time the arms are used in outstretched or overhead positions, and in heavy carrying and lifting. Simple things like taking frequent breaks, changing positions, stretching or using a hand truck or cart can bring relief. More specific treatments and exercises may be prescribed by a physician or physical therapist. Rehabilitation may begin with a few exercises to loosen up tight muscles and joints around the compressed nerves and blood vessels. To help restore normal mobility, your therapist may prescribe stretching and massage for the joints, muscles, and nerves.

Self Management

A home program of exercise is essential and must be performed consistently to produce benefits. Postural exercises Symptoms often respond to an exercise program addressing healthy posture and muscle balance. Stretching and strengthening along with awareness exercises can help achieve optimal posture.

Work management

Work hours can add up to problems. What changes can be
made to help avoid these problems?
Occupational ergonomics: A worksite specialist can evaluate your workplace to determine safe alignment, worksite postures, and work-related furniture.
Arm positions: Avoid holding your arms outward for prolonged time periods.
Work heights: Avoid overhead activities, especially if these positions bring on symptoms.
Helpful hints
Decrease tension on the shoulder straps of your seat belt.
Use rest periods to decrease fatigue.
Women with large, pendulous breasts may benefit from a strapless long-line bra.
Obese patients should seek advise for safe weight loss.
Symptom management
Shrug shoulders maximally and hold 30 to 60 seconds.
Lie on back with head tilted to the sore side.
Lie on back with shoulders partially shrugged.
Sleep modifications
If directed by your therapist, raise arms overhead for a short period immediately before going to sleep.
Avoid sleeping on your stomach.
Pinning or strapping your arm to your side limits sleeping with arms out or overhead.
Things to avoid
Heavy lifting, pulling, pushing.
Rapid breathing.
Looking up, bending the neck back.
Elevating the arms for long periods.
Carrying bags with a strap on the sore-side shoulder.
Prevention and Long Term Management
Long term management of this problem will probably have to rely on worksite alterations. Modifications may need to be made in overhead activities and heavy lifting. The primary aim, however, is to ensure healthy work and recreational postures.
Surgery for Thoracic Outlet Syndrome is usually a last resort. The surgery is directed at removing the source of compression on the nerves of the Brachial Plexus. If there is an extra rib present, this is usually removed. Otherwise, surgery consists of simply releasing the constricting elements and scar tissue around the nerves.