12.7: Actions, Origins, and Insertions of the Skeletal Muscles

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Rosanna Hartline
West Hills College Lemoore

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Actions, Origins, and Insertions of the Skeletal Muscles

Head and Face

Muscle	Action	Origin	Insertion
buccinator	pressing cheek inward, compressing air while blowing	maxilla bone, mandible bone	orbicularis oris
depressor anguli oris	opening the mouth, sliding the lower jaw right and left	mandible bone	corners of the mouth
depressor labii inferioris	drawing the lip downward	mandible bone	lower lip
epicranius	raising eyebrows, wrinkling forehead, pulling scalp posteriorly	frontal belly, occipital belly, temporal bone	skin of brow, epicranial aponeurosis
lateral pterygoid	protruding the mandible, opening the jaw, moving the mandible outward and right and left	pterygoid plate of sphenoid bone	mandible bone
masseter (superficial & deep)	elevating the mandible (lower jaw)	zygomatic arch	mandible bone
medial pterygoid	elevating the mandible, moving the mandible outward and right and left	pterygoid plate of sphenoid bone	mandible bone
mentalis	elevating and protruding lower lip and chin	mandible bone	chin
nasalis	widening the nostrils	maxilla bone	nasal bone
orbicularis oculi	closing the eye	margin of orbit	eyelid
orbicularis oris	closing the mouth, shaping lips	maxilla bone, mandible bone	corners of the mouth
risorius	pulling mouth laterally	fascia of parotid salivary gland	corners of the mouth
temporalis	elevating the mandible (lower jaw)	temporal bone	mandible bone
zygomaticus major	smiling/raising corners of the mouth	zygomatic bone	corners of the mouth (dimple region), orbicularis oris
zygomaticus minor	smiling/raising corners of the mouth	zygomatic bone	corners of the mouth

Eye

Muscle	Action	Origin	Insertion
levator palpebrae superioris	elevating and retracting the upper eyelid	sphenoid bone	upper eyelid
inferior oblique	looking up and laterally (eye roll)	maxilla bone	eyeball (inferior, lateral)
inferior rectus	looking down (depression)	sphenoid bone	eyeball (inferior, medial)
lateral rectus	looking laterally (abduction)	sphenoid bone	eyeball (lateral, anterior)
medial rectus	looking medially (adduction)	sphenoid bone	eyeball (medial)
superior oblique	looking down and laterally (eye roll)	sphenoid bone	eyeball (superior, lateral)
superior rectus	looking up (elevation)	sphenoid bone	eyeball (superior, anterior)

Anterior Neck

Muscle	Action	Origin	Insertion
digastric	depressing the mandible, elevating the larynx	mandible bone, temporal bone	hyoid bone
longus capitis	flexing the head and neck, rotating the head	cervical vertebrae	occipital bone
mylohyoid	elevating hyoid bone, elevating the floor of the mouth, depressing the mandible	mandible bone	hyoid bone
omohyoid	depressing the hyoid bone, depressing the larynx	scapula	hyoid bone
platysma	tensing skin of the neck, depressing the mandible, pulling down and back the lower lip	thoracic fascia	mandible bone, corners of mouth
scalenus anterior	flexing the neck and elevating the ribs	cervical vertebrae	first two ribs
scalenus medius	flexing the neck and elevating the ribs	cervical vertebrae	first two ribs
scalenus posterior	flexing the neck and elevating the ribs	cervical vertebrae	first two ribs
sternocleidomastoid	flexing the neck, rotating the neck, elevating the ribs	sternum, clavicle	mastoid process of temporal bone
sternohyoid	elevating the larynx	sternum, clavicle	hyoid bone
sternothyroid	depressing the hyoid bone, depressing the larynx	sternum, first costal cartilage	thyroid cartilage
stylohyoid	elevating the larynx	styloid process of temporal bone	hyoid bone
thyrohyoid	depressing the hyoid bone, elevating the thyroid	thyroid cartilage, larynx	hyoid bone

Thorax

Muscle	Action	Origin	Insertion
diaphragm	increasing thoracic volume (for inhalation)	sternum, ribs, lumbar vertebrae	central tendinous sheet
external intercostals	elevating ribs	inferior aspects of ribs	superior aspects of ribs
innermost intercostals	adducting the ribs, decreasing thoracic volume (for exhalation)	inferior aspects of ribs	superior aspects of ribs
internal intercostals	depressing ribs	superior aspects of ribs	inferior aspects of ribs
pectoralis major	flexing, adducting, and medially rotating the arm at the shoulder	sternum, clavicle	humerus
pectoralis minor	elevating the ribs, moving scapula anterior and inferior, protracting and elevating the shoulder	ribs	scapula
serratus anterior	moving and fixing scapula anteriorly, protracting the shoulder	ribs	scapula

Abdomen

Muscle	Action	Origin	Insertion
external oblique	flexing vertebral column, rotating vertebral column, compressing the abdomen	lower ribs	ilium, pubis, linea alba
internal oblique	flexing vertebral column, rotating vertebral column, compressing the abdomen	lumbar vertebrae, ilium	pubis, linea alba, lower ribs, sternum
rectus abdominis	flexing vertebral column, compressing the abdomen	pubis	lower ribs, sternum
transversus abdominis	compressing the abdomen	lower ribs, ilium, lumbar vertebrae	pubis, linea alba

Posterior Trunk

Muscle	Action	Origin	Insertion
iliocostalis (thoracis, lumborum)	flexing the vertebral column laterally, extending the vertebral column	thoracic and lumbar vertebrae, ilium, sacrum	ribs
latissimus dorsi	extending, adducting, and medially rotating arm at the shoulder	thoracic and lumbar vertebrae, ribs	humerus
levator scapulae	elevating the scapula and extending the neck	cervical vertebrae	scapula
longissimus (capitis, cervicis, thoracis)	flexing the head and neck laterally, extending the vertebral column	cervical, thoracic, and lumbar vertebrae	cervical, thoracic, and lumbar vertebrae
multifidus	extending backwards, bending vertebral column laterally, rotating vertebral column, collecting sensory information	cervical, thoracic, and lumbar vertebrae	cervical, thoracic, and lumbar vertebrae
obliquus capitis inferior	rotating the head and the neck	axis (C₂)	atlas (C₁)
obliquus capitis superior	extending and flexing the head	atlas (C₁)	occipital bone
quadratus lumborum	depress ribs, laterally flexes vertebral column	ilium, iliolumbar ligament	lumbar vertebrae, last rib
rectus capitis posterior major	extending and rotating the head	axis (C₂)	occipital bone
rectus capitis posterior minor	extending the head and neck, collecting sensory information	atlas (C₁)	occipital bone
rhomboid (major, minor)	elevating and adducting scapula	cervical and thoracic vertebrae	scapula
semispinalis (capitis, cervicis, thoracis)	extending the head and vertebral column, rotating head and vertebral column	cervical and thoracic vertebrae	occipital bone, cervical and thoracic vertebrae
serratus posterior inferior	depressing lower ribs, decreasing thoracic volume (for exhalation)	thoracic and lumbar vertebrae	lower ribs
serratus posterior superior	elevating upper ribs	cervical and thoracic vertebrae, nuchal ligament	upper ribs
spinalis thoracis	extending the neck, raising the neck and rotating it laterally	thoracic vertebrae	cervical and thoracic vertebrae
splenius capitis	extending the head, laterally flexing the head	cervical vertebrae	temporal bone, occipital bone
splenius cervicis	extending the head and neck, laterally flexing and rotating the head and neck	thoracic vertebrae	cervical vertebrae
teres major	extending and medially rotating the arm	scapula	humerus
trapezius (lower, middle, upper)	elevating, retracting, depressing, and upwardly rotating the scapula, extending the neck	occipital bone, thoracic vertebrae	scapula

Rotator Cuff

Muscle	Action	Origin	Insertion
infraspinatus	laterally rotating the shoulder	scapula	humerus
subscapularis	medially rotating the shoulder, stabilizes shoulder joint	scapula	humerus
supraspinatus	abducting the shoulder, stabilizes shoulder joint	scapula	humerus
teres minor	laterally rotating the shoulder	scapula	humerus

Arm (Shoulder to Elbow)

Muscle	Action	Origin	Insertion
biceps brachii	flexing the arm at the elbow	scapula	radius
brachialis	flexing the arm at the elbow	humerus	ulna
coracobrachialis	flexing and adducting the arm	scapula	humerus
deltoid	abducting the arm at the shoulder, flexing and extending arm at the shoulder	clavicle, scapula	humerus
triceps brachii	extending the arm at the elbow	humerus, scapula	ulna

Forearm (Elbow to Wrist)

Muscle	Action	Origin	Insertion
abductor pollicis longus	abduction and extension of the thumb	radius, ulna, interosseous membrane	first metacarpal, trapezium
anconeus	extending the elbow	humerus	ulna
brachioradialis	flexing the arm at the elbow	humerus	radius
extensor carpi radialis brevis	extending and abducting the hand	humerus	third metacarpal
extensor carpi radialis longus	extending and abducting the hand	humerus	second metacarpal
extensor carpi ulnaris	extending and adducting the hand at the wrist	humerus	carpal bones
extensor digiti minimi	extends the little finger (phalanx 5)	humerus	fifth phalanx
extensor digitorum	extending the fingers	humerus	digits
extensor indicis	extending the index finger (phalanx 2), extending the wrist	ulna, interosseous membrane	tendon of extensor digitorum of index finger
extensor pollicis brevis	extending the thumb	radius, ulna, interosseous membrane	first proximal phalanx
extensor pollicis longus	extending the thumb	radius, ulna, interosseous membrane	first proximal phalanx
flexor carpi radialis	flexing and abducting the hand at the wrist	humerus	carpal bones
flexor carpi ulnaris	flexing and adducts the hand at the wrist	humerus	carpal bones
flexor digitorum profundus	flexing distal interphalangeal joints	ulna, interosseous membrane	phalanges 2-5
flexor digitorum superficialis	flexing the wrist, flexing the phalanges 2-5	humerus, ulna, radius	phalanges 2-5
flexor pollicis longus	flexing the thumb	first distal phalanx	radius, interosseous membrane
palmaris longus	flexing the hand at the wrist	humerus	carpal bones
pronator quadratus	pronating the forearm	ulna	radius
pronator teres	pronating the forearm	humerus, ulna	radius
supinator	supinating the forearm	humerus, ulna	radius

Hand

Muscle	Action	Origin	Insertion
abductor digiti minimi	abducting and flexing the little finger (phalanx 5)	pisiform	fifth phalanx
abductor pollicis brevis	abducting the thumb	transverse carpal ligament, carpal bones	first phalanx (thumb)
abductor pollicis longus	abduction and extension of the thumb	radius, ulna, interosseous membrane	first metacarpal, trapezium
dorsal interossei	abducting and flexing metacarpal-phalanx joints	metacarpals	proximal phalanges 2-4
extensor digiti minimi	extends the little finger (phalanx 5)	humerus	fifth phalanx
extensor digitorum	extending the fingers	humerus	digits
extensor indicis	extending the index finger (phalanx 2), extending the wrist	ulna, interosseous membrane	tendon of extensor digitorum of index finger
extensor pollicis brevis	extending the thumb	radius, ulna, interosseous membrane	first proximal phalanx
extensor pollicis longus	extending the thumb	radius, ulna, interosseous membrane	first proximal phalanx
flexor digiti minimi brevis	flexing the little finger (phalanx 5)	hamate	fifth proximal phalanx
flexor digitorum superficialis	flexing the wrist, flexing the phalanges 2-5	humerus, ulna, radius	phalanges 2-5
flexor digitorum profundus	flexing distal interphalangeal joints	ulna, interosseous membrane	phalanges 2-5
flexor pollicis brevis	abducting and flexing the thumb	first metacarpal, carpal bones	first proximal phalanx
flexor pollicis longus	flexing the thumb	first distal phalanx	radius, interosseous membrane
flexor retinaculum of the wrist (a tendinous sheath)	no actions - fibrous band over carpal bones, forms carpal tunnel	n/a	n/a
lumbricals	extending the proximal and distal interphalangeal joints	tendons of flexor digitorum profundus	phalanges 2-5, tendons of extensor digitorum
opponens digiti minimi	opposition of the fifth metacarpal	flexor retinaculum, trapezium	fifth metacarpal
opponens pollicis	opposition of the thumb	flexor retinaculum, trapezium	first metacarpal
palmar interossei	adducting and flexing metacarpal-phalanx joints	metacarpals 2, 4, 5	phalanges 2, 4, 5
palmaris longus	flexing the hand at the wrist	humerus	carpal bones

Hip & Thigh

Muscle	Action	Origin	Insertion
adductor longus	adducting the thigh at the hip	pubis	femur
adductor magnus	adducting the thigh at the hip	pubis, ischium	femur
biceps femoris	flexing the leg at the knee, extending the thigh at the hip	ischium, femur	tibia, fibula
gluteus maximus	extending the thigh at the hip, rotating the thigh laterally	ilium, sacrum, coccyx	femur, iliotibial tract (iliotibial band)
gluteus medius	abducting the thigh at the hip, rotating the thigh medially	ilium	femur
gluteus minimus	abducting and medially rotating the thigh	ilium	femur
gracilis	adducting the thigh at the hip	pubis	tibia
iliacus	flexing the thigh at the hip	ilium	femur
pectineus	adducting the thigh, flexing and medially rotating the leg	pubis	femur
psoas major	flexing the thigh at the hip, flexing the vertebral column	thoracic and lumbar vertebrae	femur
quadratus lumborum	depress ribs, laterally flexes vertebral column	ilium, iliolumbar ligament	lumbar vertebrae, last rib
rectus femoris	extending the leg at the knee, flexing the thigh at the hip	ilium	tibia
sartorius	flexing the leg at the knee, flexing and rotating the thigh at the hip	ilium	tibia
semimembranosus	flexing the leg at the knee, extending the thigh at the hip	ischium	tibia
semitendinosus	flexing the leg at the knee, extending the thigh at the hip	ischium	tibia
tensor fascia latae	tensing the iliotibial band, supporting the knee	ilium	iliotibial tract (iliotibial band)
vastus intermedius	extending the leg at the knee	femur	tibia
vastus lateralis	extending the leg at the knee	femur	tibia
vastus medialis	extending the leg at the knee	femur	tibia

Leg

Muscle	Action	Origin	Insertion
extensor digitorum longus	extending the toes	tibia, fibula	digits
extensor hallucis longus	extending hallux (big toe), dorsiflexing foot	fibula, interosseous membrane	first distal phalanx
fibularis brevis	plantar flexing, everting the foot	fibula	fifth metatarsal
fibularis longus	plantarflexing	tibia, fibula	first metatarsal
fibularis tertius	dorsiflexing the foot, eversion of the foot	fibula, interosseous membrane	fifth metatarsal
flexor digitorum longus	flexing the toes	tibia	digits
flexor hallucis longus	flexing hallux (big toe)	fibula	big toe
gastrocnemius	plantarflexing	femur	calcaneus
popliteus	flexing and rotating the left medially, laterally rotates thigh	femur, lateral meniscus	tibia
soleus	plantarflexing	femur, tibia	calcaneus
tibialis anterior	dorsiflexing the foot at the ankle, inverting the foot	tibia	first metatarsal
tibialis posterior	inverting and plantar flexing the food, stabilizing longitudinal foot arch	tibia, fibula, interosseous membrane	tarsals, metatarsals 2-4

Foot

Muscle	Action	Origin	Insertion
abductor digiti minimi	abducting and flexing the small toe (phalanx 5)	calcaneus	fifth proximal phalanx
adductor hallucis	abducting and flexing hallux (big toe)	calcaneus, flexor retinaculum	first proximal phalanx
dorsal interossei	abducting and flexing middle toes at metatarsophalangeal joints, extending middle toes at interphalangeal joints	metatarsals	phalanges
extensor digitorum brevis	extending toes 2-5	calcaneus, extensor retinaculum	first proximal phalanx, extensor expansions on phalanges 2-5
extensor digitorum longus	extending the toes	tibia, fibula	digits
extensor hallucis brevis	extending hallux (big toe)	calcaneus	first proximal phalanx
extensor hallucis longus	extending hallux (big toe), dorsiflexing foot	fibula, interosseous membrane	first distal phalanx
fibularis longus	plantar flexing	tibia, fibula	first metatarsal
fibularis tertius	dorsiflexing the foot, eversion of the foot	fibula, interosseous membrane	fifth metatarsal
flexor accessorius	flexing interphalangeal joints	calcaneus, long plantar ligament	tendons of flexor digitorum longus
flexor digiti minimi brevis	flexing the small toe (phalanx 5)	Fifth metatarsal, tendon sheath of fibularis longus	fifth proximal phalanx
flexor digitorum brevis	flexing toes 2-4	calcaneus	middle phalanges 2-4
flexor digitorum longus	flexing the toes	tibia	digits
flexor hallucis brevis	flexing hallux (big toe)	tarsal bones	first proximal phalanx
flexor hallucis longus	flexing hallux (big toe)	fibula	big toe
lumbricals	extending toes 2-5 at interphalangeal joints, flexing the small toes at metatarsophalangeal joints	tendons of flexor digitorum longus	proximal phalanges 2-5
opponens digiti minimi	adducting and opposing the small toe (phalanx 5)	fifth metatarsal, long plantar ligament	fifth metatarsal
plantar interossei	abducting toes 3-5, flexing proximal phalanges, extending distal phalanges	metatarsals	phalanges
tibialis anterior	dorsiflexing the foot at the ankle, inverting the foot	tibia	first metatarsal
tibialis posterior	inverting and plantar flexing the food, stabilizing longitudinal foot arch	tibia, fibula, interosseous membrane	tarsals, metatarsals 2-4

Attributions

"Anatomy and Physiology" by J. Gordon Betts et al., OpenStax is licensed under CC BY 4.0
"Anatomy and Physiology I Lab" by Victoria Vidal is licensed under CC BY 4.0
"BIOL 250 Human Anatomy Lab Manual SU 19" by Yancy Aquino, Skyline College is licensed under CC BY-NC-SA 4.0