Thoracic Outlet Syndrome

Understanding Thoracic Outlet Syndrome

Also known as: TOS, Neurovascular Compression of the Upper Extremity Thoracic outlet syndrome is compression of the nerves or blood vessels that pass between your neck and arm — through a space bordered by the scalene muscles (which run from the cervical spine to the first rib), the first rib, the clavicle, and the pec minor muscle. Neurogenic TOS, involving the brachial plexus (the bundle of nerves supplying the arm), is the most common form. Vascular TOS, involving the subclavian artery or vein, is less frequent but more serious. TOS is one of the most commonly misdiagnosed conditions in the upper extremity — it closely mimics cervical radiculopathy, carpal tunnel syndrome, and rotator cuff pathology, which is why we screen for it systematically in anyone with upper extremity symptoms.

You may describe arm heaviness or fatigue after overhead activity, tingling along the ulnar (pinky) side of the hand, and a dull ache across the shoulder and into the chest. Sleeping with arms overhead, carrying a heavy bag, or working above shoulder height often flares symptoms. Provocative tests — Adson's, Wright's, and the Roos test (holding the arms up in a "stick-up" position for 90 seconds) — typically reproduce the pattern. Forward-head and rounded-shoulder posture shortens the scalenes and pec minor, closing down the thoracic outlet.

Previous whiplash, a cervical rib (a bony anomaly), repetitive overhead work, and hypertrophied neck muscles all raise risk. Pregnancy-related postural changes can also contribute. We open the outlet from multiple angles. First-rib mobilization restores motion to this key structural gate.

Cervical and thoracic adjustments correct the postural patterns that narrow the space. Targeted release of the anterior and middle scalenes, pec minor, and subclavius muscles using ART, myofascial release, and instrument-assisted work relieves soft-tissue compression. Brachial plexus and ulnar nerve glides restore neural mobility. Scapular retraction, deep neck flexor activation, and postural retraining rebuild the structural support.

Most neurogenic TOS improves within eight to twelve weeks. Vascular TOS — with arm swelling, color change, or absent pulse — requires vascular-surgery co-management. We may recommend: diversified adjustments, ART, myofascial release, Graston/IASTM, corrective exercise, Class IV laser, posture program Seek immediate care if: You develop sudden arm swelling, significant color change (pale or blue), coolness, loss of pulse, or severe pain — these can indicate vascular TOS requiring urgent evaluation.