Anterior Scalene
Neck
A landmark for the subclavian artery and brachial plexus — the artery passes posterior to this muscle, making it key in diagnosing thoracic outlet syndrome.
Function
Flexes/laterally flexes neck; elevates first rib
Origin
Anterior tubercles of transverse processes C3-C6
Insertion
First rib scalene tubercle
Innervation
Anterior rami C4-C6