Axial Muscles (Origin, Insertion and Action)

Occipitofrontalis Frontal Belly

Origin: epi-cranial aponeurosis

Insertion: Skin of eyebrow and bridge of nose

Action: Raises Eyebrow/ Wrinkles Forehead

Orbicularis Oculi

Origin: Medial Margin of Orbit

Insertion: Skin around eyelids

Action: Closes eye

Levator Labii Superioris

Origin: Inferior Margin of Orbit

Insertion: Orbicularis Oris

Action: Elevates upper lip

Depressor Labii Inferioris

Origin: Mandible

Insertion: Skin of lower lip

Action: depresses lower lip

Orbicularis Oris

Origin: Maxilla and Mandible

Insertion: Lips

Action: compresses/ purses lips

Mentalis

Origin: Mandible

Insertion: Skin of chin

Action: Protrudes lower lip

Sternocleidomastoid

Origin: Clavicle and Sternum

Insertion: Mastoid Process of Temporal Bone

Action: Bilaterally- flex neck

Unilaterally- laterally flex neck and turn face to opposite side

Inferior Rectus

Origin: Sphenoid Bone

Insertion: Inferior Surface

Action: eyes look down

Medial Rectus

Origin: Sphenoid Bone

Insertion: medial surface

Action: eyes look medially

Superior Rectus

Origin: Sphenoid Bone

Insertion: superior surface

Action: eyes look up

Lateral Rectus

Origin: Sphenoid Bone

Insertion: Lateral surface

Action: eyes look laterally

Inferior Oblique

Origin: Maxilla

Insertion: Inferior/ Lateral surface

Action: eye rolls/ look up

Superior Oblique

Origin: Sphenoid Bone

Insertion: Superior/ lateral surface

Action: eyes rolls/ look down

Zygomaticus Major (BENEATH zygomaticus minor)

Origin: Zygomatic Bone

Insertion: Muscles at angle of mouth

Action: elevates corner of mouth and draws it laterally

Zygomaticus Minor

Origin: Zygomatic Bone

Insertion: Upper lip

Action: elevates upper lip

Temporalis (mastication)

Origin: Temporal Bone

Insertion: coronoid process of mandible

Action: elevates/ closes jaw

Masseter (mastication)

Origin: zygomatic arch

Insertion: Mandible

Action: elevates mandible

Diaphragm (respiration)

Origin: 1. Xiphoid Process of sternum 2. Costal Cartilage Ribs 3. Lumbar Vertebrae and Discs

Insertion: Central Tendon

Action: Contracted- flattens and increases vertical dimension of thoracic cavity for inhalation

Relaxed- moves superiorly and decreases vertical dimension for exhalation

External Intercostals (POINT DOWN) (respiration)

Origin: Inferior border of rib ABOVE

Insertion: Superior Border of rib BELOW

Action: Contracted- elevates ribs, increase ante/posterior dimensions for inhalation

Relaxed- depresses ribs, decreases dimensions for exhalation

Internal Intercostals (POINT UP) (respiration)

Origin: Superior Border of rib BELOW

Insertion: Inferior Border of rib ABOVE

Action: Contracted- depresses ribs during FORCE exhalation

Rectus Abdominis (respiration) (DEEP to external obliques)

Origin: Pubic Crest/ Symphysis

Insertion: Ribs 5-7/ Xiphoid Process

Action: Flexes vertebral column and compresses abdomen

External Oblique (respiration)

Origin: Lower Ribs

Insertion: Illiac Crest of Illium/ linea alba (midline)

Action: Bilaterally (acting together)- compress abdomen/ flex vertebral column

Unilaterally (acting separately)- lateral flexion of vertebral column)

Internal Obliques (respiration) (DEEP to external oblique)

Origin: Illiac Crest of Illium

Insertion: lower 3 ribs/ linea alba (midline)

Action: Bilaterally (acting together)- compress abdomen/ flex vertebral column

Unilaterally (acting separately)- lateral flexion of vertebral column and rotates column to same side

Transverse Abdominis (respiration) (DEEP to external oblique)

Origin: Illiac Crest of Illium/ ribs

Insertion: xiphoid process of sternum/ linea alba (midline) and pubic bone

Action: Compresses abdomen

Erector Spinae

Origin: Large muscle group extending from sacrum to the base of the skull/ attaches to ribs and vertebrae along the way

Insertion: Large muscle group extending from sacrum to the base of the skull/ attaches to ribs and vertebrae along the way

Action: Bilaterally (contracting together)- extend vertebral column and maintain posture

Unilaterally (contracting separately)- rotate and laterally flex the vertebral column