DPT 744: Week 2, Suboccipital Group

Rectus capitis posterior major origin

Spinous process of C2

Rectus capitis posterior major insertion

Occipital bone

Rectus capitis posterior major action

Extension and ipsilateral rotation of head

Rectus capitis posterior major innervation

Dorsal rami C1

Rectus capitis posterior minor origin

Posterior tubercle of C1

Rectus capitis posterior minor insertion

Occipital bone

Rectus capitis posterior minor action

Extension of head

Rectus capitis posterior minor innervation

Dorsal rami C1

Obliquus capitis superior origin

Transverse process of C1

Obliquus capitis superior insertion

Occipital bone

Obliquus capitis superior action

Extension and ipsilateral lateral flexion of head

Obliquus capitis superior innervation

Dorsal rami C1

Obliquus capitis inferior origin

Spinous process of C2

Obliquus capitis inferior insertion

Transverse process of C1

Obliquus capitis inferior action

Ipsilateral rotation of head

Obliquus capitis inferior innervation

Dorsal rami C1

Sternocleidomastoid origin

Manubrium and clavicle

Sternocleidomastoid insertion

Mastoid process

Sternocleidomastoid action

Bilaterally, pulls the head anteriorly, extends head at atlanto-occipital joint, flexion of cervical spine Unilaterally, turns the chin to the opposite side

Sternocleidomastoid innervation

Spinal accessory (CN 11) and APR C2-3

Platysma origin

Fascia covering pectoralis major and deltoid

Platysma insertion

Inferior border of mandible, skin, and subcutaneous tissues

Platysma action

Draws corners of mouth inferiorly and widens it (sadness/fright) Draws skin superiorly when clenching teeth

Platysma innervation

Cervical branch of facial nerve (CN VII)