The thoracic outlet is an “opening” at the base of the neck, on both sides, where the nerves and artery that service the arm on that side exit through as they descend into the arm. It is formed by the anterior and medial scalene muscles, the first rib, and the clavicle (collar bone).
If the thoracic outlet narrows in any way, due to one or more of these structures, neurovascular compression is possible (compression of the nerves and artery). This can result in shoulder pain, neck pain, weakness in the affected arm and hand, numbness and tingling in the arm down to the hands, especially the last three fingers; and in some cases swelling of the arm. Carrying something like a heavy bag on the affected shoulder makes the symptoms worse.
In thoracic outlet syndrome there is usually a history of prior injury/trauma to the shoulder girdle, such as a car accident or sports injury. People with long necks and long arms are said to be more predisposed to this condition as the weight of the arm and length of the neck tend to put more stress in the thoracic outlet area.
Left alone without resolution, it is possible to develop permanent nerve damage resulting in chronic pain, weakness in the arm and hand, and reduced sensation in the inner arm area.
If you suspect you have thoracic outlet syndrome, see your doctor or an experienced chiropractor. There are some simple orthopedic tests that can be done to see if you likely have TOS. An MRI study can help visualize the thoracic outlet and identify if there is swelling; and needle electromyograph (EMG) can determine if the arm muscles are getting the proper amount of nerve flow.
If the diagnosis is confirmed, physical therapy exercises are usually prescribed to help open the thoracic outlet space. In some cases, imaging studies show a fibrous band responsible for compressing the neurovascular structure; in these cases surgery may be an option.
You can also try these exercises:
1) Shoulder shrugs: hold dumbbells in both hands (5-10 pounds), standing. Using your shoulders, lift up both shoulders as though you were doing an exaggerated shrug. Repeat 12 times 4-6 times a day.
2) Arm swings: Standing with arms by your side, swing the affected arm across your body (arm pointing down; do not exceed about 22 degrees angle relative to your body) repeatedly. Do it gently but not too slowly. Do not twist at the waist. If you do it correctly, this lifts the clavicle above the ribcage. Do 20 swings several times throughout the day.
3) Cervical roll: While lying down on the floor face up, place a cylindrical pillow, about 5″ diameter, right under your neck so that you feel it bend your neck into an arch. Arch your neck over the pillow and touch the crown of your head to the floor; repeat 10x. Then turn to the left and when you can’t turn any longer hold the stretch in that position for 10 seconds; then turn to right and repeat. Do 10x per side. This can help improve your posture by moving your head over your shoulders and take some pressure off the scalene muscles.
Stop immediately if you feel dizzy. Not recommended for the elderly or for anyone with cardiovascular disease, high blood pressure, history of stroke, taking blood thinner medications.
Lastly, get an experienced massage therapist who specialize in medical massage (as opposed to spa massages). These people know muscle anatomy very well and can “strip” the scalene muscles on the sides of your neck to relax them or elongate them, relieving pressure to the neurovascular bundle. Look up massage therapists who know a technique called “Active Release Technique,” or A-R-T.