Thoracic Outlet Syndrome

The symptoms: Numbness, tingling and pain in the fingers, hand and/or arm.

The culprit: mechanical compression of the brachial plexus, the subclavian artery or vein as they travel through the thoracic outlet - the small region between your collarbone, anterior ribs, and the top portion of the shoulder blade.

From Klaassen Z, Sorenson E, Tubbs RS, et al. Thoracic outlet syndrome: a neurological and vascular disorder. Clin Anat. 2014;27:724–32

TOS is a neurovascular syndrome - compression of the nerves and blood vessels that travel from the cervicothoracic junction to innervate and supply blood to the arm leads to neurologic and vascular issues. This is the mechanism leading to the pain, tingling and numbness experienced by people suffering with TOS. Ever fallen asleep on your arm and been roused from your slumber by a painful pins and needles sensation? Yeah, that same pain - caused by compression of the space between the base of the neck and armpit.

Risk Factors:

• Anatomical variations such as a cervical rib (you're not supposed to have ribs attached to your cervical vertebrae, but some people do).

• Repeated overhead movements (looking at you, Athletes) such as pressing overhead, swimming, throwing a baseball.

• Repetitive overhead motions performed at work - painting, putting boxes up on shelves, building something overhead, etc.

• Shoulder instability can cause the muscles to clamp down and overwork in an effort to stabilize the shoulder, which closes down the space around the nerves, arteries and veins.

• Hypertrophy of muscles - your big, strong muscles end up taking up space and narrowing the thoracic outlet. Combined with a spine, shoulder and ribs that aren't moving, this is the perfect recipe for TOS symptoms.

• Poor posture - forward head carriage, shoulders rounded forward, increased curvature in thoracic spine (slouching) all decrease the space available in the thoracic outlet.

Reaching overhead creates tension through the thoracic outlet as the neurovascular bundle travels under the coracoid process. Repeated overhead efforts are one of the main risk factors for developing TOS.

The most common type of TOS is nTOS, or compression specifically of the nerves. This is the type that we typically find when people come to us for help. Luckily, manual therapy is THE recommended course of treatment for nTOS.

How we can help:

• Chiropractic Adjustments

  • musculoskeletal influence - improved space and motion between spine, ribs, and shoulder

  • nervous system influence - better coordination and control of muscle tone and posture

• Soft tissue therapy

  • trigger point therapy to address tight and overworked muscles (scalenes, pec minor, serratus anterior)

• Rehabilitative exercises

  • Strengthen lengthened and weak muscles (deep neck flexors, lower and mid traps)

Sources:

1. Joshi AV, Shinde S, Chaudhary NS, Chaudhary S. Evidence-Based Diagnostic and Therapeutic Methods for Thoracic Outlet Syndrome: A Systematic Review. Cureus. 2026 May 4;18(5). doi:10.7759/cureus.108241

2. Souza TA. Neck and Neck/Arm Complaints. In: Differential Diagnosis and Management for the Chiropractor. 5th ed. Burlington, MA: Jones & Bartlett Learning; 2016. p. 77–9.