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

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    53690
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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


    This page titled 12.7: Actions, Origins, and Insertions of the Skeletal Muscles is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Rosanna Hartline.

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