19/03/2026
gran resumen.
Thoracic Outlet Syndrome: The Compression Zone of the Upper Limb
This image highlights how the brachial plexus, subclavian artery, and vein pass through narrow anatomical spaces between the scalenes, clavicle, and pec minor—making this region highly vulnerable to compression.
At the top, the scalenus anterior and medius create the first passage (interscalene triangle). This is where the brachial plexus and subclavian artery travel. Tightness or overactivity in these muscles can reduce space and begin the compression process.
As the bundle moves forward, it passes beneath the clavicle and over the first rib, forming another potential bottleneck. Any postural बदलाव—like depressed shoulders or clavicular stiffness—can increase الضغط here.
Further down, the structures pass under the pectoralis minor near the coracoid process, which is another common site of compression. A tight pec minor (often due to rounded shoulders) pulls the scapula forward and downward, narrowing this space even more.
Biomechanically, this entire pathway functions as a dynamic tunnel, not a fixed space. Its size changes with posture, breathing, and shoulder movement. That’s why symptoms often worsen with overhead activities, prolonged sitting, or poor posture.
When compression occurs, it can affect:
– Nerves (brachial plexus) → pain, tingling, numbness, weakness
– Artery → reduced blood flow, coldness, fatigue
– Vein → swelling, heaviness, discoloration
This explains why thoracic outlet syndrome is not just a neck or shoulder issue—it’s a multi-level biomechanical problem involving posture, muscle balance, and movement patterns.
👉 TOS is not just compression—it’s loss of space in a dynamic system.
