scalenus posterior (anatomy)
Last reviewed 01/2018
Scalenus posterior is one of the muscles of the posterior triangle of the neck. It is invested superficially by a layer of deep cervical fascia. It arises from the posterior tubercles of the transverse processes of the third to sixth cervical vertebrae. It inserts into the posterolateral external border of the second rib.
Scalenus posterior acts to elevate ths second rib and flexes the cervical neck area. In carrying out these actions, it can act as an accessory muscle of inspiration. It is innervated by the anterior primary rami of cervical nerves C6 to C8. Superficially lie trapezius and levator scapula. Anteriorly, it lies in relation to scalenus medius.