Lower limb muscles

Question 1

iliacus (iliopsoas)

Answer 1

origin: iliac fossa and crest, lateral sacrum
Insertion: lesser trochanter of femur
action: flex trunk at hip joint, flex thigh

Question 2

psoas major (iliopsoas)

Answer 2

origin: transverse processes, bodies, and discs of T12 and lumbar vertebrae
Insertion: lesser trochanter of femur
action: flex trunk at hip joint

Question 3

sartorius

Answer 3

origin: anterior superior iliac spine
Insertion: aponeurosis into medial aspect of proximal tibia
action: flexes, abducts, and laterally rotates thigh

Question 4

magnus (adductor)

Answer 4

origin: iscial and pubic rami and ishial tuberosity
Insertion: linea aspera and adductor tubercle of femur
action: adduct and medially rotate thigh

Question 5

longus (adductor)

Answer 5

origin: pubis near pubic symphysis
Insertion: linea aspera
action: adduct and medially rotate thigh

Question 6

brevis (adductor)

Answer 6

origin: body and interior pubic ramus
Insertion: linea aspera
action: adduct and medially rotate and flex thigh

Question 7

gracilis

Answer 7

origin: inferior ramus and body of pubis
Insertion: medial surface of tibia inferior to medial condyle
action: adducts thigh

Question 8

rectus femoris

Answer 8

origin: anterior inferior iliac spine and superior margin of acetabulum
Insertion: tibial tuberosity and patella
action: extends leg and flexes thigh

Question 9

vastus lateralis

Answer 9

origin: greater trochanter, intertrochanteric line, linea aspera
Insertion: tibial tuberosity and patella
action: extends leg and stabilizes knee

Question 10

vastus medialis

Answer 10

origin: linea aspera and intertrochanteric line
Insertion: tibial tuberosity and patella
action: extends leg, stabilizes patella

Question 11

vastus intermedius

Answer 11

origin: anterior and lateral surface of femur
Insertion: tibial tuberosity and patella
action: extends leg

Question 12

tensor fascia lata

Answer 12

origin: anterior iliac crest and anterior superior iliac spine
Insertion: iliotibial tract (lateral part of fascia lata)
action: steadies trunk

Question 13

gluteus maximus

Answer 13

origin: dorsal ilium, sacrum, and coccyx
Insertion: gluteal tuberosity of femur and iliotibial tract
action: powerful thigh extensor

Question 14

gluteus mediius

Answer 14

origin: upper lateral surface of ilium
Insertion: greater trochanter of femur
action: abducts and medially rotates thigh

Question 15

gluteus minimus

Answer 15

origin: external inferior surface of ilium
Insertion: greater trochanter of femur
action: abducts and medially rotates thigh

Question 16

biceps femoris

Answer 16

origin: ischial tuberosity (long), linea aspera and distal femur (short)
Insertion: tendon passes, head of fibula and lateral condyle of tibia
action: extends thigh

Question 17

semitendinosus

Answer 17

origin: ischial tuberosity
Insertion: medial aspect of upper tibial shaft
action: extends thigh

Question 18

semimembranosus

Answer 18

origin: ischial tuberosity
Insertion: medial condyle of tibia, lateral condyle of femur
action: extends thigh

Question 19

fibularis longus

Answer 19

origin: head and upper portion of fibula
Insertion: tendon under foot to metatarsal I and medial cuneiform
action: plantar flexes and everts foot

Question 20

fibularis brevis

Answer 20

origin: distal portion of fibula shaft
Insertion: tendon behind lateral malleolus to insert on proximal end of metatarsal V
action: plantar flexes and everts foot

Question 21

tibialis anterior

Answer 21

origin: lateral condyle, upper part of tibia, interosseous membrane
Insertion: tendon into inferior surface of first cuneiform and metatarsal I
action: prime mover of dorsiflexion

Question 22

extensor digitorus longus

Answer 22

origin: lateral condyle of tibia, proximal 3/4 of fibula, interosseous membrane
Insertion: tendon to middle and distal phalanges II-V
action: prime mover of toe extension

Question 23

fibularis tertius

Answer 23

origin: distal anterior surface of fibula and interosseous membrane
Insertion: tendon to dorsum of metatarsal V
action: dorsiflexes and everts foot

Question 24

extensor hallucis longus

Answer 24

origin: andteromedial shaft of fibula and interosseous membrane
Insertion: tendon to distal phalanx of great toe
action: extends great toe

Question 25

triceps surae

Answer 25

origin: n/a Insertion: via common tendon into calcaneus action: plantar flex foot

Question 26

gastrocnemius

Answer 26

origin: 2 heads from medial and lateral condyles of femur Insertion: calcaneus via calcaneal tendon action: plantar flexes foot

Question 27

soleus

Answer 27

origin: proximal portion of tibia and fibula, interosseous membrane Insertion: calcaneus via calcaneal tendon action: plantar flexion

Question 28

popliteus

Answer 28

origin: lateral condyle of femur and lateral meniscus Insertion: proximal tibia action: flexes and rotates leg medially

Question 29

tibialis posterior

Answer 29

origin: superior portion of tibia and fibula and interosseous membrane Insertion: tendon behind medial malleolus and under arch of foot to metatarsals II-V action: prime mover of foot inversion

Question 30

flexor digitorus longus

Answer 30

origin: posterior surface of tibia Insertion: distal phalanges of toes II-V action: flexes toes

Question 31

flexor hallucis longus

Answer 31

origin: middle portion of fibula shaft, interosseous membrane Insertion: tendon under foot to distal phalanx of great toe action: flexes great toe

Question 32

pectineus

Answer 32

origin: pectineal line or superior ramus of pubis Insertion: posterior surface of femur action: adducts, flexes, and medially rotates thigh

Question 33

piriformis

Answer 33

origin: anterior sacrum, gluteal surface of ilium Insertion: greater trochanter of femur action: laterally rotates thigh

Question 34

superior gemellus

Answer 34

origin: ischial spine Insertion: medial surface of greater trochanter action: laterally rotates thigh

Question 35

obturator internus

Answer 35

origin: inner surface of obturator membrane, bony boundaries of obturator foramen Insertion: medial surface of greater trochanter of femur action: laterally rotates thigh

Question 36

inferior gemellus

Answer 36

origin: ischial tuberosity Insertion: medial surface of greater trochanter of femur action: laterally rotates thigh

Question 37

quadratus femoris

Answer 37

origin: ischial tuberosity Insertion: intertrochanteric crest of femur action: laterally rotates thigh