Insertions, Origins, and Actions

Buccinator

Origin: Maxilla

Insertion: Corner of the mouth

Action: Draws the corner of the mouth laterally.

Corrugator supercilii

Origin: Nasal bridge and orbicularis oculi

Insertion: Skin of the eyebrow

Action: Depresses the middle part of the eyebrows and brings them together as in frowning.

Depressor labii inferioris

Origin: Lower border of the mandible

Insertion: Skin of the lower lip and orbicularis oris

Action: Depresses the lower lip

Levator labii superioris

Origin: Maxilla

Insertion: Skin and orbicularis oris of the upper lip

Action: Raises upper lip like a sneer.

Occipitofrontalis

Origin: Occipital bone

Insertion: Skin of the eyebrow and nose Action: Moves scalp, raises eyebrows, wrinkles forehead.

Orbicularis oris

Origin: Nasal septum, maxilla, and mandible Insertion: Fascia and lip muscle

Action: Closes lips and causes 'pursing'

Orbicularis oculi

Origin: Frontal bone and maxilla

Insertion: Skin of the eyelids

Action: Closes eyes: blinking, winking, squinting.

Platysma

Origin: Fascia of the deltoid and pectoralis major

Insertion: Skin covering the inferior border of the mandible

Action: Brings the lower lip down and wrinkles neck and chin skin.

Risorius

Origin: Fascia of the masseter

Insertion: Corner of your mouth

Action: Pulls the mouth laterally

Zygomaticus

Origin: Zygomatic bone

Insertion: Orbicularis oris of the upper lip Action: Lifts the corner of the mouth up like a smile.

Temporalis

Origin: Temporal bone

Insertion: Coronoid process of the mandible

Action: Keeps the jaw elevated/closed regularly.

Masseter

Origin: Zygomatic arch

Insertion: Angle + ramus of mandible

Action: Prime mover of jaw elevation.

Lateral pterygoid

Origin: Lateral side of the lateral pterygoid plate of the sphenoid

Insertion: Mandibular condyle

Action: Opens the jaw and moves it forward and side to side.

Medial pterygoid

Origin: Pterygoid plate

Insertion: Inside edge of mandible

Action: Closes the jaw and moves it forward and side to side.

Genioglossus

Origin: Mandible

Insertion: Surface of the tongue

Action: Sticks tongue out.

Styloglossus

Origin: Styloid process of the temporal bone Insertion: sides and tip of tongue

Action: Sticks tongue out and pulls it back in.

Hyoglossus

Origin: Hyoid bone

Insertion: Side of the tongue

Action: Retracts the tongue into the mouth.

Sternocleidomastoid

Origin: Sternum and clavicle

Insertion: Mastoid process (temporal) nuchal line (occipital)

Action: Activate both for 'yes' or 'no' motion.

Splenius capitus

Origin: Upper part of the vertebral column Insertion: Back of the head

Action: One muscle contracts: tilts the head.

Trapezius

Origin: base of occiput spinous processes

Insertion: spine of scapula, acromion process clavicle

Action: Extend (look up) the head.

Iliocostalis

Insertion: Always superior to the origin

Action: Can extend the vertebral column, but also laterally flex the head.

Longissimus

Insertion: Always superior to the origin

Action: Only extends the vertebral column.

Spinalis

Insertion: Always superior to the origin

Action: Only extends the vertebral column.

External intercostals

Origin: Superior rib

Insertion: Inferior rib

Action: Elevates during inspiration.

Internal intercostals

Origin: Inferior rib

Insertion: Superior rib

Action: Depresses during expiration.

Thoracic diaphragm

Origin: Sternum, ribs, and lumbar vertebrae

Insertion: Central tendon

Action: Inspiration.

Rectus abdominis

Origin: Pubic bone

Insertion: Xiphoid process of the sternum Action: Flexes the vertebral column

External oblique

Origin: Ribs

Insertion: Pelvis

Action: Flexes and rotates the vertebral column.

Internal oblique

Origin: Iliac crest

Insertion: Lower ribs

Action: Flexes and rotates the vertebral column.

Transverse abdominis

Action: Compresses the abdominal wall.

Quadratus lumborum

Origin: Iliac crest and lumbar region Insertion: Lumbar vertebrae

Action: Laterally flexes.

Levator scapula

Origin: C1-C4

Insertion: Scapula

Action: Elevates and protracts the scapula

Pectoralis minor

Origin: Rib 3-5

Insertion: Scapula (coracoid process)

Action: Depresses scapula.

Serratus anterior

Origin: Ribs 1-9

Insertion: Scapula

Action: Protracts scapula.

Latissimus dorsi

Origin: Lumbar area

Insertion: Single tendon that inserts into the intertubercular groove

Action: Adducts and extends.

Pectoralis major

Origin: Upper part of the rib cage/Clavicle Insertion: Intertuberular groove

Action: Adduct and flex.

Biceps brachii

Origin: Scapula

Insertion: Radial tuberosity

Action: Flexes elbow and shoulder.

Brachialis

Origin: Humerus

Insertion: Coronoid process (ulna)

Action: Flex elbow.

Triceps brachii

Origin: Scapula and humerus

Insertion: Olecranon process (ulna)

Action: All 3 heads can extend the elbow

Flexor carpi radialis

Origin: Medial epicondyle

Insertion: 2nd and 3rd metacarpal

Action: Flexes wrist.

Palmaris longus

Origin: Medial epicondyle

Insertion: Palmar fascia

Action: Flexes wrist.

Flexor digitorum superficialis

Origin: Medial epicondyle

Insertion: Middle phalanx

Action: Flexes digits at knuckles.

Flexor digitorum profundus

Origin: Radius

Insertion: Distal phalanx (tip of fingers)

Action: Flexes digits within fingers.

Extensor carpi radialis

Origin: Lateral epicondyle

Insertion: 2nd and 3rd metacarpal

Action: Extends wrist.

Extensor carpi ulnaris

Origin: Lateral epicondyle

Insertion: 5th metacarpal

Action: Extends wrist.

Extensor digitorum

Origin: Lateral epicondyle

Insertion: Over digits 2-5

Action: Extends wrist.

Extensor pollicis

Insertion: Thumb

Action: Extends the thumb.

Iliacus

Origin: Iliac fossa

Insertion: Less trochanter

Action: Flexes hip.

Psoas

Origin: Thoracic vertebrae

Insertion: Lesser trochanter

Action: Flexes hip.

Gluteus maximus

Origin: Posterior surface of the ilium Insertion: Gluteal tuberosity

Action: Extension.

Gluteus medius

Origin: Lateral side of coxal bone

Insertion: Greater trochanter

Action: Abduct.

Gluteus minimus

Origin: Lateral side of coxal bone

Insertion: Greater trochanter

Action: Abduct.

Tensor Fasciae Latae

Origin: Ilium

Insertion: Tibia

Action: Stabilizes femur on top of tibia when standing.

Rectus femoris

Origin: Above the hip joint

Insertion: Anterior iliac spine

Action: Extends knee and can flex hip.

Vastus muscles

Origin: Femur

Insertion: Patellar ligament

Action: Extends knee

Sartorius

Origin: Iliac spine (above hip joint)

Insertion: Tibia

Action: Flex hip and knee.

Biceps femoris

Origin: Ischial tuberosity (long)

Insertion: Fibula head

Action: Flex knee, extends hip.

Semimembranosus

Origin: Ischial tuberosity

Insertion: Tibia

Action: Flex knee, extend hip.

Semitendinosus

Origin: Ischial tuberosity

Insertion: Tibia

Action: Flex knee, extend hip

Adductors (longus, brevis, magnus)

Origin: Pubis

Insertion: Back of femur

Action: Adduct thigh.

Tibialis anterior

Action: Extends digits.

Fibularis brevis

Origin: Lateral side of the tibia

Insertion: 5th metatarsal

Action: Evert.

Fibularis longus

Origin: Lateral side of the tibia

Insertion: 1st metatarsal

Action: Evert.

Gastrocnemius

Origin: Condyles of femur

Insertion: Tendon of calcaneus

Action: Plantar flexes the foot and can flex knee.

Plantaris

Origin: Femur

Insertion: Tendon of calcaneus

Action: Plantar flexes the foot and can flex knee.

Soleus

Origin: Fibula and tibia

Insertion: Calcaneus tendon

Action: Plantar flex foot.

Flexor digitorum

Origin: Tibia

Insertion: Distal phalanx 2-5

Action: Flex toes.