Muscles of the Neck and Vertebral Column

Sternocleidomastoid

Origin: manubrium of sternum and medial 1/3 of clavicle; Insertion: mastoid process of temporal bone; Action: head/neck flex, ipsilateral lateral flexion and contralateral rotation of neck/head

Anterior Scalene

Origin: transverse process C3-C6; Action: 1st rib; Action: ipsilateral lateral flexion and rotation of neck, cervical flexion, rib elevation

Middle Scalene

Origin: transverse process C2-C7; Action: 1st rib; Action: ipsilateral lateral flexion and rotation of neck, cervical flexion, rib elevation

Posterior Scalene

Origin: transverse process C5-C7; Insertion: 2nd rib; Action: ipsilateral lateral flexion and rotation of neck, cervical flexion, rib elevation

Splenius Capitis

Origin: spinous process of cervical and thoracic vertebrae; Insertion: mastoid process and occipital bone; Action: extension if head, lateral flexion of c-spine, ipsilateral rotation

Erector Spinae Group

Spinalis, longissimus, and Iliocostalis—Origin: common tendon (thoracolumbar fascia) that attaches to posterior surface of sacrum, iliac crest, spinous process of all lumbar and last two thoracic vertebrae; Insertion: various attachments—posterior ribs, spinous and transverse processes of thoracic and cervical vertebrae, and mastoid process; Action: Unilaterally—ipsilateral lateral flexion of vert. column, bilaterally—extension of vert. column

Quadratus Lumborum

Origin: iliac crest; Insertion: transverse process of lumbar vertebrae and 12th rib; Action: lateral flexion of lumbar spine, extension and stabilization of lumbar spine