Muscle · Neck

Middle scalene

Musculus scalenus medius

The middle scalene is the largest of the three, running from almost every neck vertebra down to the top of the first rib, behind the groove for the subclavian artery. It side-bends the neck and lifts the first rib in inspiration. Together with the anterior scalene it forms the interscalene gap — the narrow triangle that the nerve trunks of the brachial plexus and the subclavian artery must pass through — which is why the scalenes get attention whenever neck problems arrive with symptoms travelling into the arm.