Muscle Origins, Insertions, Actions - Thigh, Leg & Foot

Front 1

Tensor fascia lata

Back 1

Origin:
anterior aspect of iliac crest
anterior superior iliac spine (ASIS)
Insertion: anterior aspect of IT band, below greater trochanter
Action:
hip flexion
medially rotate & abduct a flexed thigh
tenses IT tract to support femur on the tibia during standing

Front 2

Gluteus maximus

Back 2

Origin:
outer rim of ilium (medial aspect)
dorsal surface of sacrum and coccyx
sacrotuberous ligament
Insertion:
IT band (primary insertion)
gluteal tuberosity of femur
Action:
powerful extensor of hip
laterally rotates thigh
upper fibers aid in abduction of thigh
fibers of IT band stabilize a fully extended knee

Front 3

Gluteus medius

Back 3

Origin:
outer aspect of ilium (between iliac crest and anterior and posterior gluteal lines)
upper fascia (AKA gluteal aponeurosis)
Insertion: superior aspect of greater trochanter
Action:
anterior and lateral fibers abduct and medially rotate the thigh
posterior fibers may laterally rotate thigh
stabilizes the pelvis and prevents free limb from sagging during gait

Front 4

Gluteus minimus

Back 4

Origin: outer aspect of ilium (between anterior and inferior gluteal lines)
Insertion:
greater trochanter (anterior to medius)
articular capsule of hip joint
Action:
abduct and medially rotate the thigh
stabilizes the pelvis and prevents free limb from sagging during gait

Front 5

Piriformis

Back 5

Origin: pelvic surface of sacrum (anterior portion)
Insertion: medial surface of greater trochanter (through greater sciatic foramen)
Action:
lateral rotation of extended thigh
abducts a flexed thigh

Front 6

Quadratus femoris

Back 6

Origin: lateral aspect of ischial tuberosity
Insertion: quadrate line (along posterior aspect of femur and intertrochanteric crest)
Action: laterally rotates femur

Front 7

Semitendinosus

Back 7

Origin: ischial tuberosity
Insertion:
medial aspect of tibial shaft
contributes to the pez anserine
Action:
extends hip
flexes knee
medially rotates tibia

Front 8

Semimembranosus

Back 8

Origin: ischial tuberosity
Insertion:
posterior medial aspect of medial tibial condyle
fibers join to form most of oblique popliteal ligament (& medial meniscus)
Action:
flexes knee
extends hip
medially rotates tibia
pulls medial meniscus posterior during flexion

Front 9

Biceps femoris

Back 9

Origin:
long head: ischial tuberosity
short head: lateral lip of linea aspera and the lateral intermuscular septum
Insertion:
head of fibula
maybe to the lateral tibial condyle
Action:
flexor at the knee (mainly short head)
laterally rotates thigh if flexed at the knee
extends hip (long head)

Front 10

Adductor longus

Back 10

Origin: anterior surface of pubis, just inferior to the pubic tubercle
Insertion: medial lip of linea aspera on middle half of femur
Action:
adducts thigh
flexes thigh
may laterally rotate thigh at the hip

Front 11

Adductor brevis

Back 11

Origin: body & inferior ramus of pubis
Insertion: superior portion of linea aspera
Action:
adducts thigh (major)
aids in flexion of thigh
may laterally rotate thigh at the hip

Front 12

Adductor magnus

Back 12

Origin:
anterior fibers: inferior pubic ramus
oblique fibers: ischial ramus
posterior fibers: ischial tuberosity
Insertion:
proximal 1/3 of linea aspera
adductor tubercle
Action:
adducts the thigh
posterior fibers also extend and laterally rotate thigh

Front 13

Gracilis

Back 13

Origin: body of pubis & inferior pubic ramus
Insertion:
medial surface of proximal tibia, inferior to tibial condyle
contributes to the pez anserine
Action:
adducts thigh
flexes knee
medially rotates tibia

Front 14

Sartorius

Back 14

Origin: anterior superior iliac spine (ASIS)
Insertion:
upper medial surface of body of tibia
contributes to pez anserine
Action:
flexes hip and knee
laterally rotates thigh if flexed at the hip

Front 15

Rectus femoris

Back 15

Origin:
anterior head: anterior inferior iliac spine (AIIS)
posterior head: ilium just above the acetabulum
Insertion:
common quadriceps tendon into patella
tibial tuberosity via patellar ligament
Action:
extends knee
flexes hip

Front 16

Vastus lateralis

Back 16

Origin:
greater trochanter
lateral lip of linea aspera
lateral intermuscular septum
Insertion:
common quadriceps tendon into patella
tibial tuberosity via patellar ligament
Action:
extends knee
can abnormally displace patella

Front 17

Vastus intermedius

Back 17

Origin: anterior lateral aspect of the femoral shaft
Insertion:
common quadriceps tendon into patella
tibial tuberosity via patellar ligament
Action: extends knee

Front 18

Vastus medialis

Back 18

Origin:
intertrochanteric line of femur
medial aspect of linea aspera
Insertion:
common quadriceps tendon into patella
tibial tuberosity via patellar ligament
Action: extends knee

Front 19

Psoas major

Back 19

Origin:
transverse processes of L1-L5
vertebral bodies of T12-L4 and the intervening intervertebral discs
Insertion: iliopsoas tendon to the lesser trochanter of the femur
Action:
hip flexion
lateral rotation

Front 20

Illiacus

Back 20

Origin: inner surface of upper iliac fossa
Insertion: iliopsoas tendon to the lesser trochanter of the femur
Action:
powerful hip flexion
lateral rotation

Front 21

Pectineus

Back 21

Origin:
pectineal line of the pubis
superior pubic ramus
Insertion:
the pectineal line of the femur
(just below the lesser trochanter on the posterior aspect of the femur)
Action:
flexes hip
adducts thigh
medially rotates thigh

Front 22

Gastrocnemius

Back 22

Origin:
medial head: just above medial condyle of femur
lateral head: just above lateral condyle of femur
Insertion: calcaneus via lateral portion of calcaneal tendon
Action:
plantarflex the ankle
knee flexion (when not weight bearing)
stabilizes ankle & knee when standing

Front 23

Soleus

Back 23

Origin:
upper fibula
soleal line of tibia
Insertion: calcaneus via medial portion of calcaneal tendon
Action: plantarflex the foot

Front 24

Plantaris

Back 24

Origin: above the lateral head of gastrocnemius on femur
Insertion: calcaneus, medial to calcaneal tendon, or blending with the calcaneal tendon
Action: like a weak gastrocnemius

Front 25

Popliteus

Back 25

Origin:
lateral femoral condyle
arcuate popliteal ligament
lateral meniscus
knee joint capsule
Insertion: posterior tibial surface above the soleal line
Action:
insertion fixed: laterally rotates femur on tibia & unlocks knee
origin fixed: medially rotates tibia on femur & unlocks knee

Front 26

Flexor digitorum longus

Back 26

Origin:
posterior surface of tibia
crural fascia
Insertion: plantar surface of bases of the 2-5th distal phalanges
Action:
primarily flexes 2nd - 5th toes
weak plantarflexor
weak inversion & adduction of foot

Front 27

Tibialis posterior

Back 27

Origin:
posterior, proximal tibia
interosseous membrane
medial surface of fibula
Insertion:
navicular tuberosity (principle)
all 3 cuneiforms (plantar surface)
bases of 2nd-4th metatarsals
cuboid
sustentaculum tali of calcaneus
Action:
stabilizes ankle
inversion & adduction of foot
prevents hyperpronation while in gait
weak plantarflexion of ankle

Front 28

Peroneus longus

Back 28

Origin:
head of the fibula
proximal 2/3 of lateral fibula
adjacent intermuscular septum
Insertion:
plantar surface of cuboid
base of 1st & (2nd) metatarsal
plantar surface of medial cuneiform
Action:
eversion & abduction of the foot
weak plantarflexion of the foot at the transverse tarsal joint

Front 29

Peroneus brevis

Back 29

Origin:
distal 2/3 of lateral fibula
posterior and anterior intermuscular septum
Insertion: tuberosity on lateral aspect of base of 5th metatarsal
Action:
eversion & abduction of the foot
weak plantarflexion of foot

Front 30

Tibialis anterior

Back 30

Origin:
lateral tibial condyle
proximal 2/3 of anteriolateral surface of tibia
interosseous membrane
anterior intermuscular septum & crural fascia
Insertion:
medial & plantar surface of base of 1st metatarsal
medial & plantar surface of the cuneiform
Action:
strongest dorsiflexor
inverts & adducts the foot

Front 31

Extensor digitorum longus

Back 31

Origin:
lateral condyle of the tibia
upper anterior surface of fibula
interosseous membrane
crural fascia
Insertion:
dorsal surface of the bases of the middle & distal phalanxes of the 2nd-5th rays
(via 4 tendons and giving a fibrous expansion)
Action:
extends the lateral 4 toes
weak dorsiflexor & everts foot

Front 32

Quadratus plantae

Back 32

Origin:
medial head: medial calcaneus
lateral head: lateral calcaneus & long plantar ligament
Insertion:
lateral margin of tendon of flexor digitorum longus (FDL)
may send slips into the distal tendons
Action:
assists FDL in flexing the distal phalanxes of 2nd-5th toes
corrects FDL from pulling toes medially

Front 33

Lumbricals

Back 33

Origin: from tendons of FDL:
1st: medial aspect of tendon to 2nd ray
2nd-4th: two heads between the tendons in which they lie
Insertion: extensor tendons of EDL on dorsal foot
Action:
flex proximal phalanges at MTP
extend middle & distal phalanges at IP