Temporal bone (Petrous and Squamous parts)

Authors

Affiliations

Nathaniel Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Attachment sites

Mastoid process

Table 1: Muscles originating from the Mastoid Process

Muscle	Origin	Insertion	Innervation	Action

Table 2: Muscles Inserting on the Mastoid Process

Muscle	Origin	Insertion	Innervation	Action
Splenius capitis	Nuchal lig. C7-T4 SP	Lateral third of nuchal line Mastoid process	Spinal nn. Posterior rami (lateral br.) C1 - C6	Bilateral: Head and neck extension Unilateral: I/L sidebend, I/L rotation
Sternocleidomastoid	Manubrium Medial third of Clavicle	Mastoid process Superior nuchal line	CN XI Accessory n. Cervical plexus C2 - C4	Unilateral: I/L cervical sidebend, C/L cervical rotation Bilateral: Head extension, Cervical Flexion, Assists in respiration, Prevents posterior translation during mastication SCJ stabilization

Palpation

• Follow the base of the occiput toward its lateral edge
• The rounded, most lateral prominence is the mastoid process