Scalenus anterior muscle

The scalene muscles are a group of three pairs of muscles in the lateral neck, namely the anterior scalene, middle scalene, and posterior scalene.

They are innervated by the fourth, fifth, and sixth cervical spinal nerves (C4-C6). The anterior and middle scalene muscles lift the first rib and bend the neck to the same side; the posterior scalene lifts the second rib and tilts the neck to the same side. The muscles are named from Ancient Greek σκαληνός (skalenos) 'uneven'.