Lower Limb

Question 1

gluteus maximus

Answer 1

Origin: illium posterior to posterior gluteal line, dorsal surface of sacrum and coccyx, sacrotuberous ligament

Insertion: upper fibers: iliotibial tract (lateral condyle of tibia); lowermost fibers: gluteal tuberosity of the femur

Action: extends flexed thigh; assists in laterally rotating the femur; abducts thigh

Innervation: inferior gluteal nerve

Blood Supply: inferior gluteal artery, some superior gluteal artery

Question 2

gluteus medius

Answer 2

Origin: lateral surface of ilium between anterior and posterior gluteal lines

Insertion: lateral surface of the greater trochanter of femur

Action: abducts and medially rotates thigh at hips; steadies pelvis on leg when opposite leg is raised

Innervation: superior gluteal nerve

Blood Supply: superior gluteal artery

Question 3

gluteus minimus

Answer 3

Origin: lateral surface of ilium between anterior and posterior gluteal lines

Insertion: anterior surface of the greater trochanter of femur

Action: abducts and medially rotates thigh at hips; steadies pelvis on leg when opposite leg is raised

Innervation: superior gluteal nerve

Blood Supply: main trunk and deep branch of superior gluteal artery

Question 4

tensor faciae latae

Answer 4

Origin: anterior superior iliac spine and anterior part of iliac crest

Insertion: iliotibial tract that attaches to lateral condyle of tibia

Action: abducts, medially rotates, and flexes thigh at hip; helps to keep knee extended

Innervation: superior gluteal nerve

Blood Supply: ascending branch of lateral circumflex femoral artery

Question 5

piriformis

Answer 5

Origin: anterior surface of sacral segments 2-4, sacrotuberous ligament

Insertion: superior border of greater trochanter of femur

Action: laterally rotates extended thigh, abducts flexed thigh at hip

Innervation: ventral rami of L5, S1, S2

Blood Supply: superior and inferior gluteal arteries, internal pudendal artery

Question 6

obturator internus

Answer 6

Origin: pelvic surface of obturator membrane and surrounding bone

Insertion: medial surface of the greater trochanter of the femur

Action: laterally rotates extended thigh, abducts flexed thigh at hip

Innervation: nerve to obturator internus

Blood Supply: internal pudendal and obturator arteries

Question 7

superior gemellus

Answer 7

Origin: outer surface of ischial spine

Insertion: medial surface of greater trochanter of femur

Action: laterally rotates extended thigh at hip

Innervation: nerve to obturator internus

Blood Supply: inferior gluteal and internal pudendal arteries

Question 8

inferior gemellus

Answer 8

Origin: ischial tuberosity

Insertion: medial surface of great trochanter of femur

Action: laterally rotates extended thigh at the hip

Innervation: nerve to quadratus femoris

Blood Supply: medial circumflex femoral artery

Question 9

quadratus femoris

Answer 9

Origin: lateral margin of ischial tuberosity

Insertion: quadrate tubercle on intertrochanteric crest of femur

Action: laterally rotates thigh at hip

Innervation: nerve to quadrate femoris

Blood Supply: medial circumflex femoral artery

Question 10

obturator externus

Answer 10

Origin: margins of obturator foramen, obturator membrane

Insertion: trochanteric fossa of femur

Action: laterally rotates thigh, stabilizes head of femur in acetabulum

Innervation: obturator nerve

Blood Supply: medial circumflex femoral artery, obturator artery

Question 11

semitendinosus

Answer 11

Origin: ischial tuberosity

Insertion: superior part of medial surface of tibia

Action: flexes leg, extends thigh

Innervation: sciatic nerve (tibial division)

Blood Supply: perforating branch of profunda femoris, medial circumflex femoral arteries

Question 12

semimembranosus

Answer 12

Origin: ischial tuberosity

Insertion: posterior part of medial surface of tibia

Action: flexes leg, extends thigh

Innervation: sciatic nerve (tibial division)

Blood Supply: perforating branch of profunda femoris, medial circumflex femoral arteries

Question 13

biceps femoris

Answer 13

Origin: Long head: ischial tuberosity
Short head: linea aspera, lateral supracondyar line of femur

Insertion: lateral side of head of fibula

Action: flexes and laterally rotates leg, extends thigh at hip

Innervation: Long head: sciatic nerve (tibial division)
Short head: sciatic nerve (common fibular division)

Blood Supply: perforating branches of profunda femoris, inferior gluteal, circumflex femoral arteries

Question 14

pectineus

Answer 14

Origin: superior ramus of pubis

Insertion: pectineal line of femur

Action: adducts and flexes thigh at hip

Innervation: femoral nerve (sometimes obturator nerve)

Blood Supply: medial circumflex femoral artery, obturator artery

Question 15

psoas major (iliopsoas)

Answer 15

Origin: transverse processes of lumbar vertebrae, sides of bodies of T12-L5 vertebrae, intervening intervertebral disks

Insertion: lesser trochanter of femur

Action: flexes hip, flexes vertebral column laterally, used to balance trunk in sitting postion, flexes trunk

Innervation: ventral rami of first lumbar nerve

Blood Supply: lumbar branches of iliolumbar artery

Question 16

iliacus (iliopsoas)

Answer 16

Origin: superior 2/3 of iliac fossa, iliac crestm ala of sacrum, anterior sacro-iliac ligament

Insertion: lesser trochanter of femur and shaft inferior to it, to psoas major tendon

Action: flexes thigh at hips and stabilizes hip joint, acts with psoas major

Innervation: femoral nerve

Blood Supply: iliac branches of iliolumbar artery

Question 17

psoas minor (iliopsoas)

Answer 17

Origin: Bodies of T12 and L1 and intervening intervertebral discs

Insertion: Fascia over the psoas major and iliacus

Action: Flexion of thigh at hip, assists in extension of the lumbar spine

Innervation: Ventral primary rami of L1

Blood Supply: Iliolumbar artery from internal iliac artery

Question 18

sartorius

Answer 18

Origin: anterior superior iliac spine and superior part of notch below it

Insertion: superior part of the medial surface of the tibia

Action: abducts, laterally rotates, and flexes the thigh; flexes knee joint

Innervation: femoral nerve

Blood Supply: femoral artery

Question 19

rectus femoris (quadriceps femoris)

Answer 19

Origin: anterior inferior iliac spine and ilium superior to acetabulum

Insertion: base of the patella and to tibial tuberosity via patellar ligament

Action: extends leg at knee joint and flexes thight at hip joint

Innervation: femoral nerve

Blood Supply: femoral artery

Question 20

vastus lateralis (quadriceps femoris)

Answer 20

Origin: greater trochanter, lateral lip of line aspera of femur

Insertion: base of patella and to tibial tuberosity via patellar ligament

Action: extends leg at knee joint

Innervation: femoral nerve

Blood Supply: lateral circumflex femoral and profunda femoris arteries

Question 21

vastus medialis (quadriceps femoris)

Answer 21

Origin: intertochanteric line, medial lip of linea asper of femur

Insertion: base of patella and to tibial tuberosity via patellar ligament

Action: extends leg at knee joint

Innervation: femoral nerve

Blood Supply: lateral cricumflex femoral and profunda femoris artery

Question 22

vastus intermedius (quadriceps femoris)

Answer 22

Origin: anterior and lateral surfaces of body of femur

Insertion: base of patella and to tibial tuberosity via patellar ligament

Action: extends leg at knee joint

Innervation: femoral nerve

Blood Supply: lateral cricumflex femoral and profunda femoris artery

Question 23

adductor longus

Answer 23

Origin: body of pubis inferior to pubic crest

Insertion: middle line of linea aspera of femur

Action: adducts thigh at hip

Innervation: obturator nerve (anterior division)

Blood Supply: profunda femoris and medial circumflex arteries

Question 24

adductor brevis

Answer 24

Origin: body and inferior pubic ramus

Insertion: pectineal line and proximal part of linea aspera of femur

Action: adducts thigh at hip, weak hip flexor

Innervation: obturator nerve

Blood Supply: profunda femoris, medial circumflex femoral, and obturator arteries

Question 25

gracilis

Answer 25

Origin: body and inferior ramus of pubis Insertion: superior part of medial surface of tibia Action: adducts thigh, flexes and medially rotates leg Innervation: obturator nerve Blood Supply: profunda femoris artery, medial circumflex femoral artery

Question 26

adductor magnus

Answer 26

Origin: adductor part: inferior pubic ramus, ramus of ischium; hamstring part: ??? Insertion: adductor part: gluteal tuberosity, linea aspera, medial supracondylar line; hamstring part: adductor tubercle of femur Action: adductor part: adducts and flexes thigh; hamstring part: extends thigh Innervation: adductor part: obturator nerve; hamstring part: sciatic nerve (tibial division) Blood Supply: femoral, profunda femoris, and obturator arteries

Question 27

tibialis anterior

Answer 27

Origin: lateral condyle, proximal half of lateral tibia, interosseus membrane Insertion: medial plantar surfaces of medial cuneiform and base of 1st metatarsal Action: dorsiflexes foot at ankle inverts foot Innervation: deep fibular nerve Blood Supply: anterior tibial artery

Question 28

extensor digitorum longus

Answer 28

Origin: lateral condyle of tibia, proximal 3/4 of anterior surface of interosseous membrane Insertion: middle and distal phalanges of the lateral four digits Action: extends lateral four digits and dorsiflexes foot at ankle Innervation: deep fibular nerve Blood Supply: anterior tibial artery

Question 29

extensor hallucis longus

Answer 29

Origin: middle part of anterior surface of fibula and interosseous membrane Insertion: dorsal aspect of base of distal phalanx of great toe Action: extends great toe, dorsiflexes foot at ankle Innervation: deep fibular nerve Blood Supply: anterior tibial artery

Question 30

fibularis peroneus tertius

Answer 30

Origin: distal third of anterior surface of fibula and interosseous membrane Insertion: dorsum of base of 5th metatarsal Action: dorsiflexes foot at ankle and aids in eversion of foot Innervation: deep fibular nerve Blood Supply: anterior tibial artery

Question 31

fibularis peroneus longus

Answer 31

Origin: head and proximal 2/3 of lateral fibula Insertion: plantar base of 1st metatarsal and medial cuneiform Action: everts foot and weakly plantarflexes foot at ankle Innervation: superficial fibular nerve Blood Supply: anterior tibial and fibular arteries

Question 32

fibularis peroneous brevis

Answer 32

Origin: distal 2/3 of lateral surface of fibula Insertion: dorsal surface of tuberosity on lateral side of 5th metatarsal Action: everts foot and weakly plantarflexes foot at ankle Innervation: superficial fibular nerve Blood Supply: anterior tibial and fibular arteries

Question 33

gastrocnemius

Answer 33

Origin: lateral head:lateral aspect of the lateral condyle of the femur medial head: popliteal surface above medial condyle of femur Insertion: posterior aspect of calcaneus via calcaneal tendon Action: plantarflexes foot at ankle joint, assists in flexion of knee joint, raises heel during walking Innervation: tibial nerve Blood Supply: popliteal and posterior tibial arteries

Question 34

soleus

Answer 34

Origin: posterior aspect of head of fibula, proximal 1/4 of posterior surface of fibula, soleal line of tibia Insertion: posterior aspect of calcaneus via calcaneal tendon Action: plantarflexes foot at ankle, stabilizes leg over foot Innervation: tibial nerve Blood Supply: popliteal, posterior tibial, fibular arteries

Question 35

plantaris

Answer 35

Origin: inferior end of lateral supracondylar line of femur and oblique popliteal ligament Insertion: posterior aspect of calcaneus via calcaneal tendon Action: weakly assists gastrocnemius Innervation: tibial nerve Blood Supply: popliteal artery

Question 36

popliteus

Answer 36

Origin: lateral aspect of lateral condyle of femur, lateral meniscus Insertion: posterior tibia superior to soleal line Action: weakly flexes knee and unlocks it by rotating femur on fixed tibia Innervation: tibial nerve (L4-S1) Blood Supply: inferior medial and lateral genicular arteries

Question 37

flexor hallucis longus

Answer 37

Origin: distal 2/3 of posterior fibula and interosseous membrane Insertion: base of distal phalanx of great toe Action: flexes all joints of great toe, weakly plantar flexes foot at ankle Innervation: tibial nerve Blood Supply: fibular artery

Question 38

flexor digitorum longus

Answer 38

Origin: medial part of posterior tibia inferior to soleal line Insertion: plantar bases of proximal distal phalanges of lateral four digits Action: flexes lateral four digits and plantarflexes foot at ankle, supports longitudinal arches of foot Innervation: tibial nerve Blood Supply: posterior tibial artery

Question 39

tibialis posterior

Answer 39

Origin: posterior tibia below soleal line, interosseous memebrane, proximal half of posterior fibula Insertion: tuberosity of navicular bone, all cueniforms, cuboid, and bases of 2nd-4th metatarsals Action: plantarflexes foot at ankle, inverts foot Innervation: tibial nerve Blood Supply: fibular artery

Question 40

abductor hallucis

Answer 40

Origin: medial tubercle of tuberosity of calcaneus, flexor retinaculum, and plantar aponeurosis Insertion: medial side of base of proximal phalanx of 1st digit Action: abducts and flexes 1st digit Innervation: medial plantar nerve Blood Supply: medial plantar and 1st plantar metatarsal arteries

Question 41

flexor digitorum brevis

Answer 41

Origin: medial tubercle of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septum Insertion: both sides of middle phalanges of lateral four digits Action: flexes 2nd-5th digits Innervation: medial plantar nerve Blood Supply: medial and lateral plantar arteries and plantar arch, plantar metatarsal and plantar digital arteries

Question 42

abductor digiti minimi

Answer 42

Origin: medial and lateral tubercles of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septum Insertion: lateral side of base of proximal phalanx of 5th digit Action: abducts and flexes 5th digit Innervation: lateral plantar nerve Blood Supply: medial-lateral plantar artery, plantar metatarsal and plantar digital arteries to 5th digit

Question 43

quadratus plantae

Answer 43

Origin: medial and lateral sides of plantar surface of calcaneus Insertion: posterolateral edge of flexor digitorum longus tendon Action: corrects for oblique pull of flexor digitorum longus tendon, thus assists in flexion of toes Innervation: lateral plantar nerve Blood Supply: medial and lateral plantar arteries, deep plantar arterial arch

Question 44

lumbricals

Answer 44

Origin: tendons of flexor digitorum longus Insertion: medial side of dorsal digital expansions of lateral 4 digits Action: flexes proximal phalanges at MTP joint, extends phalanges at PIP and DIP joints Innervation: medial one: medial plantar nerve lateral three: lateral plantar nerve Blood Supply: lateral plantar artery and plantar metatarsal arteries

Question 45

flexor hallucis brevis

Answer 45

Origin: plantar surfaces of cuboid and lateral cuneiform Insertion: both sides of base of proximal phalanx of 1st digit Action: flexes proximal phalanx of 1st digit Innervation: medial plantar nerve Blood Supply: medial plantar artery, first plantar metatarsal artery

Question 46

adductor hallucis

Answer 46

Origin: oblique head: bases of 2nd-4th metatarsals transverse head: ligaments of MTP joints of digits 3-5 Insertion: lateral to side of base of base of proximal phalanx of 1st digit Action: adducts 1st digit, maintains transverse arch of foot Innervation: deep branch of lateral plantar nerve Blood Supply: medial and lateral plantar arteries, plantar arch, plantar metatarsal arteries

Question 47

flexor digiti minimi brevis

Answer 47

Origin: base of 5th metatarsal Insertion: lateral base of proximal phalanx of 5th digit Action: flexes proximal digit of 5th digit Innervation: superficial branch of lateral plantar nerve Blood Supply: lateral plantar artery, plantar digital artery to 5th digit, arcuate artery

Question 48

plantar interossei

Answer 48

Origin: bases and medial sides of 3rd-5th metatarsals Insertion: medial sides of bases of proximal phalanges of digits 3-5 Action: adduct digits (2-4), flex MTP joint, and extend phalanges Innervation: lateral plantar nerve Blood Supply: lateral plantar artery, plantar arch, plantar metatarsal and plantar digital arteries

Question 49

dorsal interossei

Answer 49

Origin: Adjacent sides of 1st-5th metatarsals Insertion: 1st: medial side of proximal phalanx of 2nd digit 2nd-4th: lateral dies of digits 2-4 Action: abducts 2nd-4th toes, flex MTP joints, extend planages Innervation: lateral plantar nerve Blood Supply: arcuate artery, dorsal and plantar metatarsal arteries

Question 50

extensor digitorum brevis

Answer 50

Origin: superolateral surface of calcaneus, lateral talocalcaneal ligament, cruciate crural ligament Insertion: lateral sides of tendons of extensor digitorum longus to digits 2-4 Action: aids the extensor digitorum longus in extending 4 medial digits at the MTP and interphalangeal joints Innervation: deep fibular nerve Blood Supply: dorsalis pedis, lateral tarsal, arcuate, fibular arteries

Question 51

extensor hallucis brevis

Answer 51

Origin: superolateral surface of calcaneus, lateral talocalcaneal ligament, cruciate crural ligament Insertion: dorsal aspect of base of proximal phalanx of first digit Action: aids the extensor hallicus longus in extending 1st digits at the MTP Innervation: deep fibular nerve Blood Supply: dorsalis pedis, lateral tarsal, arcuate, fibular arteries