You have abnormal sensations in the upper and lower arm and/or the hand. Sensations like pins and needles, tingling, prickling, even burning. The arm might feel weak. There is possibly a deep, boring pain in the neck and shoulder. Muscles in the upper back of the affected side may be painful as well. Possibly you have already received a diagnosis for the problem or you might not have known what it is called.
What causes thoracic outlet syndrome?
A bundle of nerves and blood vessels that innervate and supply blood to the upper extremity exits from each side of the neck and on one side or another gets compressed, causing the symptoms. This bundle consists of the brachial plexus and the subclavian artery and vein. As it travels toward the lower extremity, it can get compressed in three areas.
- It first passes between the anterior and medial scalene muscles on the side of the neck. The bundle can get compressed when they are tight.
- It then passes under the clavicle and can get compressed against the first rib.
- It then passes under the pectoralis minor of the chest and can get compressed when this muscle is tight.
Another cause is not common. Approximately 3% of people have an anatomical anomaly in the form of a small rib or extended transverse process on the 7th cervical vertebra. This can put pressure on the neurovascular bundle.
How does one get thoracic outlet syndrome?
- From sports that involve repetitive movement of the upper extremities. Or from occupations that require the same, or that require working with arms in front of the body for long periods.
- From bad posture—a chronic slouching which creates an exaggerated curve of the thoracic spine (kyphosis) and forward shoulders and head, causing the scalene and pectoralis muscles to shorten. This postural problem is called “upper cross syndrome” and is common among dentists, painters, electricians, computer workers, etc.
- From carrying a heavy backpack or a heavy load in the arms for a long period. This puts pressure on the clavicle and compresses the area between the clavicle and first rib, between which the bundle passes.
- From irregular respiration. Some people breath from the top of the chest rather than deeper from the diaphragm and hence overuse the scalene and pectorals minor muscles, which as I said above, are two areas where the neurovascular bundle can get compressed..
Prognosis
If posture is good, there should be noticeable relief of symptoms with 2-4 treatments over a two week period. If the posture is bad, more treatments will be required over a longer period of time–perhaps 6-8 over a 3-4 week period. To help with the postural issue, we will have to treat tight muscles with acupuncture and myofascial release techniques to stretch them.(1)
Treatment Strategy
- I treat the local areas using techniques from modern, orthopedic acupuncture—releasing trigger points in the scalene muscles and the pectoralis minor, which may be directly compressing the neuromuscular bundle. In the same way, I also treat other tight and painful muscles, such as the upper trapezius, the rhomboids and the levator scapulae—whatever needs to be done.
- During the same treatment, I also employ more traditional acupuncture techniques to activate the acupuncture meridians that traverse the affected areas and to balance the energy of the whole body, which facilitates the healing process.
- To further stretch and release tight muscles, I like to use a technique called proprioceptive neuromuscular facilitation (PNF for short), which definitely enhances the effect of the acupuncture.
In some patients with upper cross syndrome, the pelvis will also be out of balance, usually with an excess lordotic curve. This pelvic tilting is called “lower cross syndrome.” In such cases, the best and longest relief can be obtained if this condition is corrected as well.
(1) Matt Callison, L.Ac., Sports Medicine Acupuncture, San Diego, CA. Acusport Education, 2019, p 321