Outline 7 part 3 – muscle origins, insertions, and actions
Additional Terminology
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Retinaculum – region in which tendon groups from different muscles pass under one connective
tissue band. Wrist retinacula include the flexor and extensor retinacula of the hand
Ramus- An arm or a branch of a bone, in particular those of the ischium and pubis or of the
jawbone
Extensor carpi radialis longus – CAR pye RAY dee AL iss
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Origin: Lateral supracondylar ridge of humerus
Insertion: Base of 2nd metacarpal
Action: Extends wrist; aids in radial flexion of wrist
Extensor carpi radialis brevis – BREV iss
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Origin: Lateral epicondyle of humerus
Insertion: Base of metacarpal III
Action: Extends wrist; aids in radial flexion of wrist
Pronator teres – PRO nay tur TERR eez
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Origin: Humeral shaft near medial epicondyle; coronoid process of ulna
Insertion: Lateral surface of radial shaft
Action: Assists pronator quadratus in pronation, but only in rapid or forceful action; weakly
flexes elbow
Flexor carpi radialis –
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Origin: Medial epicondyle of humerus
Insertion: Base of metacarpals II-III
Action: Flexes wrist anteriorly; aids in radial flexion of wrist
Palmaris longus – pal MERR is
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Origin: Medial epicondyle of humerus
Insertion: Flexor retinaculum, palmer aponeurosis
Action: Anchors skin and fascia of palmar region; resists shearing forces when stress is applied to
skin
Flexor carpi ulnaris– FLEX ur CAR pye
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ul NAY ris
Origin: Medial epicondyle of humerus; medial margin of olecranon; posterior surface of ulna
Insertion: Pisiform; hamate; metacarpal V
Action: Flexes wrist anteriorly; aids in flexion of wrist
Flexor digitorum superficialis– DIDJ ih TOE rum SOO per FISH ee AY lis
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Origin: Medial epicondyle of humerus; ulnar colaterial ligament; coronoid process; superior half
of radius
Insertion: Middle phalanges II-V
Action: Flexes wrist, metacarpophalangeal, and interphalangeal joints, depending on action of
other muscles
Flexor digitorum profundus–
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Origin: Proximal three-quarters of ulna; coronoid process; interosseous membrane
Insertion: Distal phalanges II-V
Action: Flexes wrist, metacarpophalangeal, and interphalangeal joints, depending on action of
other muscles
Flexor Pollicis Longus– PAHL ih sis
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Origin: Radius; interosseous membrane
Insertion: Distal phalanx I
Action: Flexes phalanges of thumb
Pronator Quadratus- PRO nay tur quad RAY tus
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Origin: Anterior surface of distal ulna
Insertion: Anterior surface of distal radius
Action: Prime mover of forearm pronation; also resists separation of radius and ulna when force
is applied to forearm through wrist
Extensor Digitorum Communis
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Origin: Lateral epicondyle of humerus
Insertion: Dorsal surfaces of phalanges II-V
Action: Extends wrist, metacarpophalangeal, and interphalangeal joints, tends to spread fingers
apart when extending metacarpophalangeal joints
Extensor digiti minimi- DIDJ ih ty MIN ih my
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Origin: Lateral epicondyle of humerus
Insertion: Proximal phalanx of V
Action: Extends wrist and all joints of little finger
Extensor Carpi Ulnaris
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Origin: Lateral epicondyle of humerus; posterior surface of ulnar shaft
Insertion: Base of metacarpal V
Action: Extends and fixes wrist when fist is clenched or hand grips an object; aids in ulnar flexion
of wrist
Supinator- SOO pih NAY tur
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Origin: Lateral epicondyle of humerus, supinator crest and fossa of ulna just distal to radial notch;
anular and radial collateral ligaments of elbow
o Anular ligament – fibers that encircle the head of the radius
o Radial collateral ligament- triangular ligamentous structure on the lateral side of the
elbow
Insertion: Radial one-third of radius
Action: Supinates forearm, as in turning a doorknob
Abductor Pollicis Longus- PAHL iss is
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Origin: Posterior surfaces of radius and ulna; interosseous membrane
Insertion: Trapezium; base of metacarpal I
Action: Abducts thumb; extends thumb at carpometacarpal joint
Extensor Pollicis Longus- PAHL iss is
 Origin: Posterior surface of ulna; interosseous membrane
 Insertion: Distal phalanx I
 Action: Extends distal phalanx I; aids in extending phalanx I and metacarpal I; adducts and
laterally rotates thumb
Abductor pollicis brevis
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Origin: Flexor retinaculum; also scaphoid, trapezium
Insertion: Radial one-third of radius
Action: Abducts Thumb
Opponens pollicis- op PO nenz
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Origin: Trapezium; flexor retinaculum
Insertion: Metacarpal I
Action: Flexes metacarpal I to oppose thumb to fingertips
Flexor pollicis brevis
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Origin: Trapezium; trapezoid; capitate; anterior ligaments of wrist; flexor retinaculum
Insertion: Proximal phalanx I
Action: Flexes metacarpal I to oppose thumb to fingertips
Abductor digiti minimi
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Origin: Pisiform; tendon of flexor carpi ulnaris
Insertion: Medial surface of proximal phalanx V
Action: Abducts little finger, as in spreading fingers apart
Adductor Pollicis
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Origin: Capitate; bases of metacarpals II-III; anterior ligaments of wrist; tendon sheath of flexor
carpi radialis
Insertion: Medial surface of proximal phalanx I
Action: Draws thumb toward palm
Dorsal Interossei
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Origin: Bipennate from inner aspects of shafts of all metacarpals
Insertion: Proximal phalanges
Action: Abduct from axis of middle finger; flex metacarpophalangeal joint while extending
interphalangeal joints
Gluteus Maximus
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Origin: Posterior gluteal line of ilium, on posterolateral suface from iliac crest to posterior
superior spine; coccyx; posterior surface of lower sacrum
Insertion: Gluteal tuberosity of femur; lateral condyle of tibia via iliotibial tract
Action: Extends thigh at hip as in stair climbing or running and walking. Abducts thigh; elevates
trunk after stooping; extends waist after bending forward
Gluteus Medius
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Origin: Most of lateral surface of ilium between crest and acetabulum
Insertion: Greater trochanter of femur
Action: Abduct and medially rotate thigh; during walking, shift weight of trunk toward limb with
foot on the ground as other foot is lifted
Piriformis- PIR ih FOR mis
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Origin: Anterior surface of sacrum; gluteal surface of ilium; capsule of sacroiliac joint
Insertion: Greater trochanter
Action: Laterally rotates extended thigh; abducts flexed thigh
Gemellus superior- jeh MEL us
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Origin: Ischial spine
Insertion: Greater trochanter
Action: Laterally rotates extended thigh; abducts flexed thigh
Obturator Internus- OB too RAY tur
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Origin: Inner surface of obturator membrane and rim of pubis and ischium bordering membrane
Insertion: Greater trochanter
Action: Thought to laterally rotate extended thigh and abduct flexed thigh
Gemellus inferior
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Origin: Ischial tuberosity
Insertion: Greater trochanter
Action: Lateral rotates extended thigh; abducts flexed thigh
Quadratus femoris- quad RAY tus
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FEM oh ris
Origin: Ischial tuberosity of femur
Insertion: Intertrochanteric crest
Action: Laterally rotates thigh
Tensor faciae latae- TEN sur FASH ee ee LAY tee
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Origin: Iliac crest; anterior superior spine; deep surface of fascia lata
Insertion: Lateral condyle of tibia via iliotibial tract
Action: Extends knee, laterally rotates tibia, aids in abduction and medial rotation of femur;
during standing, steadies pelvis on femoral head and steadies femoral condyles on tibia
Sartorius
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Origin: On and near anterior superior spine of ilium
Insertion: Medial surface of proximal end of tibia
Action: Aids in knee and hip flexion, as in sitting or climbing; abducts and laterally rotates thigh
Vastus medialis
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Origin: Femur at intertrochanteric line; spiral line; linea aspera, and medial supracondylar line
Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia
Action: Extends knee; retains patella in groove on femur during knee movements
Vastus lateralis
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Origin: Femur at greater trochanter, intertrochanteric line, gluteal tuberosity, and line aspera
Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia
Action: Extends knee; retains patella in groove on femur during knee movements
Rectus Femoris- FEM oh ris
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Origin: Ilium at anterior inferior spine and superior margin of acetabulum; capsule of hip joint
Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia
Action: Extends the knee, as in kicking a ball or rising from a chair
Vastus Intermedius
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Origin: Anterior and lateral surfaces of femoral shaft
Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia
Action: Extends the knee
Gracilis- GRASS ih lis
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Origin: Body and inferior ramus of pubis; ramus of ischium
Insertion: Medial surface of tibia just below condyle
Action: Flexes and medially rotates tibia at knee
Adductor Longus
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Origin: Body and inferior ramus of pubis
Insertion: Linea aspera of femur
Action: Adducts and medially rotates thigh at hip
Adductor Magnus
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Origin: Inferior ramus of pubis; ramus and tuberosity of ischium
Insertion: Linea aspera; gluteal tuberosity, and medial supracondylar line of femur
Action: Adducts and medially rotates thigh; extends thigh at hip
Semitendinosus- SEM ee TEN din OH sus
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Origin: Ischial tuberosity
Insertion: Medial surface of upper tibia
Action: Flexes knee; medially rotates tibia on femur when knee is flexed; medially rotates femur
when hip is extended
Biceps Femoris
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Origin: Long head: Ischial tuberosity; Short head: linea aspera and lateral supracondylar line of
femur
Insertion: Head of fibula
Action: Flexes knee; extends hip; elevates trunk from stooping posture; laterally rotates tibia on
femur when knee is flexed; laterally rotates femur when hip is extended
Psoas Major- SO ass
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Origin: Bodies and intervertebral discs of vertebrae T12-L5; transverse processes of lumbar
vertebrae
Insertion: Lesser trochanter and nearby shaft of femur
Action: Flexes thigh at hip when trunk is flexed, as in stair climbing; flexes trunk at hip when
thigh is fixed, as in bending forward in a chair or sitting up in bed; balances trunk during sitting
Iliacus- ih LY uh cus
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Origin: Iliac crest and fossa; superolateral region of sacrum; anterior sacroiliac and iliolumbar
ligaments
Insertion: Lesser trochanter and nearby shaft of femur
Action: Flexes thigh at hip when trunk is flexed, as in stair climbing; flexes trunk at hip when
thigh is fixed, as in bending forward in a chair or sitting up in bed; balances trunk during sitting
Tibialis Anterior- TIB ee AY lis
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Origin: Lateral condyle and lateral margin of proximal half of tibia; interosseous membrane
Insertion: Medial cuneiform; metatarsal I
Action: Dorsiflexes and inverts foot; resists backward tipping of body
Extensor Digitorum Longus- DIDJ ih TOE rum
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Origin: Lateral condyle of tibia; shaft of fibula; interosseous membrane
Insertion: Middle and distal phalanges II-V
Action: Extends toes; dorsiflexes foot; tautens plantar aponeurosis
Peroneus Longus
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Origin: Head and lateral surface of proximal two-thirds of fibula
Insertion: Medial cuneiform; metatarsal I
Action: Maintains concavity of sole during toe-off and tiptoeing; everts and plantar flexes foot
Peroneus Brevis
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Origin: Lateral surface of distal two-thirds of fibula
Insertion: Base of metatarsal V
Action: Maintains concavity of sole during toe-off and tiptoeing
Gastrocnemius- GAS trock NEE me us
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Origin: Condyles and popliteal surface of femur; lateral supracondylar line; capsule of knee joint
Insertion: Calcaneus
Action: Plantar flexes foot; flexes knee; active in walking, running, and jumping
Soleus- SO lee us
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Origin: Posterior surface of head and proximal one-fourth of fibula; middle one-third of fibula;
middle one-third of tibia; interosseous membrane
Insertion: Calcaneuus
Action: Plantar flexes foot; steadies leg on ankle during standing
Popliteus- pop LIT ee us
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Origin: Lateral condyle of femur; lateral meniscus and joint capsule
Insertion: Posterior surface of upper tibia
Action: Rotates tibia medially on femur if femur is fixed, or rotates femur laterally on tibia if tibia
is fixed; unlocks to allow flexion
Flexor digitorum longus
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Origin: Posterior surface of tibial shaft
Insertion: Distal phalanges II-V
Action: Flexes phalanges of digits II-V as foot is raised from ground; stabilizes metatarsal heads
and keeps distal pads of toes in contact with ground in toe-off and tiptoe movements
Flexor hallucis longus- ha LOO sis
 Origin: Inferior two-thirds of fibula and interosseous membrane
 Insertion: Distal phalanx I
 Action: Flexes phalanges of great toe, stabilizes 1st metatarsal and keeps pad of first toe in
contact with ground
Tibialis posterior
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Origin: Posterior surface of proximal half of tibia, fibula, and interosseous membrane
Insertion: Navicular, medial cuneiform, metatarsals II-IV
Action: Inverts foot; may assist in plantar flexion or control pronation of foot during walking
Extensor hallucis longus
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Origin: Anterior surface of middle of fibula, interosseous membrane
Insertion: Distal phalanx I
Action: Extends great toe; dorsiflexes foot
Extensor digitorum brevis
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Origin: Calcaneus; inferior extensor retinaculum of ankle
Insertion: Proximal phalanx I; tendons of extensor digitorum longus to middle and distal
phalanges II-IV
Action: Extends proximal phalanx I and all phalanges of digits II-IV
Abductor digiti minimi
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Origin: Calcaneus; plantar aponeurosis
Insertion: Proximal phalanx V
Action: Abducts and flexes little toe; supports arches of foot
Flexor digitorum brevis
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Origin: Calcaneus; plantar aponeurosis
Insertion: Middle phalanges II-V
Action: Flexes digits II-IV; supports arches of foot
Abductor Hallucis
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Origin: Calcaneus; plantar aponeurosis; flexor retinaculum
Insertion: Proximal phalanx I
Action: Abducts great toe; supports arches of foot
Flexor Hallucis Brevis
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Origin: Cuboid; lateral cuneiform; tibialis posterior tendon
Insertion: Proximal phalanx I
Action: Flexes great toe
Lumbricals- LUM brih culs
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Origin: Tendon of flexor digitorum longus
Insertion: Proximal phalanges II-V
Action: Flexes toes II-V
Flexor Digiti Minimi Brevis
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Origin: Metatarsal V; sheath of peroneus longus
Insertion: Proximal phalanx V
Action: Flexes little toe
Dorsal Interossei
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Origin: Each with two heads arising from facing surfaces of two adjacent metatarsals
Insertion: Proximal phalanges II-IV
Action: Abduct toes II-IV