Which postural defect commonly contributes to Thoracic Outlet Syndrome?

Which postural defect commonly contributes to Thoracic Outlet Syndrome?

• A. Forward head and rounded shoulders
• B. Hyperlordosis of the lumbar spine
• C. Pelvic tilt
• D. Flat feet

Answer: (A)

Forward head with rounded shoulders changes the position of the shoulder girdle, protracting the scapulae and increasing internal rotation of the arms. This tightens the muscles around the thoracic outlet, especially the scalene muscles and the pectoralis minor, and can elevate or crowd the first rib. The result is reduced space for the brachial plexus and nearby vessels as they pass between the neck and arm, making compression more likely during arm elevation or sustained postures. That direct mechanism is what links this particular postural defect to Thoracic Outlet Syndrome. The other options involve the lower spine or feet and don’t create the same space restriction around the thoracic outlet, so they’re not as commonly implicated in TOS.

Forward head with rounded shoulders changes the position of the shoulder girdle, protracting the scapulae and increasing internal rotation of the arms. This tightens the muscles around the thoracic outlet, especially the scalene muscles and the pectoralis minor, and can elevate or crowd the first rib. The result is reduced space for the brachial plexus and nearby vessels as they pass between the neck and arm, making compression more likely during arm elevation or sustained postures. That direct mechanism is what links this particular postural defect to Thoracic Outlet Syndrome.

The other options involve the lower spine or feet and don’t create the same space restriction around the thoracic outlet, so they’re not as commonly implicated in TOS.