08/30/2025
What Is Thoracic Outlet Syndrome?
Thoracic Outlet Syndrome is a condition where the nerves and/or blood vessels (arteries or veins) are compressed in the thoracic outlet — the narrow space between your collarbone and first rib.
Types
1. Neurogenic TOS – most common (about 90%). Compression of the brachial plexus (nerve bundle).
2. Venous TOS – compression of a vein. Can lead to swelling, blood clots, or bluish color in the arm.
3. Arterial TOS – compression of an artery. Rare but serious; can cause coldness, paleness, or pain in the hand/arm.
Causes / Risk Factors
Poor posture (forward head, rounded shoulders)
Repetitive motions (e.g., hair stylists, athletes, massage therapists, office workers)
Trauma (whiplash, fall, repetitive strain)
Anatomical differences (cervical rib, extra tight scalene muscles, narrow outlet space)
Symptoms
Neck, shoulder, and arm pain
Tingling, numbness, or weakness in the arm or hand
Swelling or discoloration (in vascular types)
Heaviness or fatigue in the arm with activity
Headaches (especially if scalene muscles are tight)
Massage can be very helpful, especially for neurogenic TOS, because it often involves muscular tightness. Helpful approaches:
Releasing scalenes, pec minor, and subclavius (common compressive muscles)
Addressing upper trapezius and levator scapulae tension
Encouraging diaphragmatic breathing to reduce accessory breathing muscle overuse.
Strengthening rhomboids, lower traps.
