Movement of Head and Neck Muscles

Obliquus capitis superior

Action: Rotates head to same side O: Transverse processes of atlas I: Inferior nuchal line of occipital bone Picture: D

Scalene muscle

Anterior, middle, and posterior Action: Flexes neck and elevate 1st and 2nd ribs during inspiration (breathing in) O: Transverse process of cervical vertebrae I: Superior surface of 1st and 2nd ribs

Posterior neck muscle

Muscles responsible for mainly rotating the head Picture: Splenius capitis and splenius cervicis is not shown

Splenius cervicis

Unilateral action: Rotation of head to same side Bilateral action: Extends head/neck O: Ligamentum nuchae (septum that extends from occipital protuberance to spine of C7) I: Occipital bone/mastoid process of temporal bone

Rectus Capitis Posterior Minor

Action: Extends head/neck O: Posterior tubercle of atlas I: Inferior nuchal line of occipital bone Picture: B

Rectus Capitis Posterior Major

Action: Extends head/neck O: Spinous process of axis I: Inferior nuchal line of occipital bone Picture: A

Obliquus capitis inferior

Action: Rotates head to same side O: Spinous process of axis I: Transverse process of atlas Picture: C

Anterolateral neck muscle

Head movement is controlled by both head and neck muscles O: Vertebral column, thoracic cage, and pectoral girdle I: Cranial bones These muscles can have more than 1 action: Unilateral - one muscles (left or right) is contracting Bilateral - both the left and right muscles are contracting Picture: cannot see posterior scalene muscle, next to the other scalene muscles but can only be seen posteriorly

Sternocleidomastoid

Unilateral action: Rotation of head to opposite side - if right side of this muscle contracts, head turns to the left side Bilateral action: Flexes neck O: Manubrium and sternal end of clavicle I: Mastoid process

Longissimus capitis

Unilateral action: Rotation of head to same side Bilateral action: Extends head/neck O: Transverse process of T1-T4 and articular processes of C4-C7 I: Mastoid process

Splenius capitis

Unilateral action: Rotation of head to same side Bilateral action: Extends head/neck O: Ligamentum nuchae (septum that extends from occipital protuberance to spine of C7) I: Occipital bone/mastoid process of temporal bone