Thoracic outlet is the clinical designation. It is also referred to anatomically as the thoracic inlet, essentially a hole surrounded by a bony ring, consisting of the first thoracic vertebra (posteriorly), the first pair of ribs (laterally), and the superior border of the sternum (anteriorly), through which several vital structures pass.
Thoracic Outlet Syndrome (TOS) is a collective name for several variations of nerve or vascular compressions near the base of the neck and upper rib cage. It is easily misdiagnosed because of the difficulty distinguishing between a cervical rib problem, a cervical disc problem or carpal tunnel. My work focuses on TOS involving compression of the neurovascular bundle, (brachial plexus) passing between the anterior and middle scalenes (neck muscles), compressing the nerves and brachial artery of the brachial plexus.
The brachial plexus is a complex web of spinal nerves coming from the cervical spine through the axilla (armpit) and under the clavicle (collarbone), innervating (supplying motor and sensory nerve fibers) the upper extremities, chest, shoulder, and arms. It emerges between the anterior and middle scalene muscles (neck) passes underneath the clavicle into the shoulder and arm. Impingement of the plexus in the scalenes, ribs, and clavicles is responsible for TOS.
Main symptoms are numbness, tingling, and pain–almost always present, sharp, burning, or aching down the arms and hands, side of the neck, and the chest, just below the clavicle, the armpit area, and upper back. One hand colder than the other, and weakness is common.
The most common causes of TOS include physical trauma from car accidents, on-the- job repetitive strain injuries, sports-related activities, poor posture, and anatomical defects such as having an extra rib. During pregnancy joints loosen, making it easier to develop bad posture, and TOS symptoms can occur for the first time.
TOS treatment is similar to the protocol for carpal tunnel syndrome and can usually be relieved by thorough balancing muscles in the neck, shoulder, and cervical areas. If the treatment does not eliminate the problem, I refer my clients out for diagnosis by an orthopedic physician, which may include x-rays and most likely an MRI.