Thoracic Outlet Syndrome (TOS) can be a tricky diagnosis. All the structures which may cause symptoms need to be vetted against those in the neck (like radiculopathies) and those throughout the arm (like peripheral nerve entrapments). While it may seem neurogenic-focused, docs need to consider vascular issues (DVTs in the upper extremity) and even a lot of muscular referrals through the upper extremity, neck, and head can come from this area too!

  • Neurogenic: Myelopathy, Peripheral Entrapments, Radiculopathy, DOUBLE CRUSH, some headaches

  • Disc: Typical IVD presentation. Extent of damage variable

  • Muscles/Joint: Scalenes and anterior shoulder muscles. Rib motion and scapulothoracic rhythm may play a role.

  • Systemic/Other: Rheumatic (AS, RA, DISH), pancoast tumor, Vascular (DVT), angina.



Anterior & Middle Scalenes, Clavicle, top ribs, and muscles of the coracoid process (pec minor, coracobrachialis, bicep short head) need to be systematically evaluated if TOS screens implicate the region.

Ensure to differentiate nerve and vascular supply!

Rotator Cuff muscles may have referral patterns down the arm (and even to the wrists and hands!). Keep this in mind when evaluating. In this case, review concepts and corrections of the SICK scapula.

Take it Further

Khadilkar outlines a number of rare types of brachial plexopathies that the more seasoned doc might consider looking into:

  • Idiopathic Brachial Plexophaty/Neuritis (Parsonage-Turner Syndrome) - Sudden disabling pain attributed as a sequelae to numerous conditions. Followed by weakness of shoulder girdle.

  • Idiopathic Hypertrophic Brachial Neuritis - Similar to PTS but with little or no pain and more motor findings.

  • Hereditary Neuralgic Amyotrophy - dominant gene-linked disorder with paralysis and sensory disturbances.

  • Cancer-related brachial plexopathy - either from metastatic spread or secondary to radiation therapy

  • Metastatic Brachial Plexopathy - lung & breast mets to plexus

  • Traumatic Brachial Plexopathy - Mechanism with elevated arm, lower plexus injury. Mechanism with arm down or to top of shoulder, upper plexus injury.

Best Practices

When considering best practice assessment and presentation of TOS, consider the following:

  • Onset 20-60 y/o, peak incidence in 30s

  • Female to Male ratio 9:1

  • Orthos LESS likely to help with diagnosis - Adson’s & Roo’s

  • Orthos MOST beneficial - Halstead, Wright’s, Cyriax Release


Of course, the specific anatomy which causes the most sensitivity needs to be treated. Especially if there is an immediate reduction of symptoms in the office. As a chiropractor, there is a often the question of “do I need to adjust this patient and if so, where?” For this question I’ll offer two approaches. First, the nerves of the brachial plexus originate from the cervical spine, so it stands to reason that treatment of the vertebral joints in the neck would help reduce potential irritation along the path of the nerves. So if this concept fits your ideology of treatment, go for it! Second, there is sympathetic innervation to the brachial plexus which originates from T2-T10 spinal levels. Treating the joints in this area may help to autonomically regulate the activity of the brachial plexus. Again, if this concept fits your doctrine include it in your management.