Muscle · Neck

Anterior scalene

Musculus scalenus anterior

The anterior scalene is the front-most of three deep, ladder-like muscles running from the sides of the neck vertebrae down to the first two ribs. It side-bends the neck, helps flex it, and with the neck held still it lifts the first rib to help you breathe in. It matters clinically out of all proportion to its size: the nerves to the arm — the brachial plexus — and the subclavian artery pass through the narrow gap between it and the middle scalene, so problems here can present as symptoms travelling into the arm. It is also one of the accessory breathing muscles that takes over when breathing becomes shallow and high in the chest.