Some attachments Leg

Question 1

Pectineus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 1

1) Superior ramus of pubis
2) Pectineal line of femur (inferior to lesser trochanter)
3) Femoral nerve L2 (possibly branch from obturator)
4) Adducts and flexes thigh; assists with medial rotation of thigh

Question 2

Psoas major

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 2

1) Sides of T12-L5 vertebrae and discs between them; transverse processes of all lumbar vertebrae
2) Lesser trochanter of femur
3) Anterior rami of lumbar nerves (L1, L2, some L3)
4) Flex thigh at hip joint and stabilization of joint

Question 3

Psoas minor

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 3

1) Sides of T12-L1 vertebrae and intervertebral discs
2) Pectineal line, iliopectineal eminence via iliopectineal arch
3) Anterior rami of lumbar nerves (L1, L2)
4) Flex thigh at hip joint and stabilization of joint

Question 4

Iliacus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 4

1) Iliac crest, iliac fossa, ala of sacrum, and anterior saco-iliac ligaments
2) tendon of psoas major, lesser trochanter, and femur distal to it
3) Femoral nerve (L2, some L3)
4) Flex thigh at hip joint and stabilization of joint

Question 5

Sartorius

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 5

1) ASIS and superior part of notch inferior to it
2) Superior part of medial surface of tibia
3) Femoral nerve (L2, L3)
4) Flexes, abducts, and laterally rotates thigh at hip joint, flexes leg at knee joint (medially rotating leg when knee is flexed)

Question 6

Rectus Femoris

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 6

1) Anterior inferior iliac spine and ilium superior to acetabulum
2) Quadriceps tendon and independent attachments to base of patella, tibial tuberosity via patellar ligament
3) Femoral nerve (L3, L4, some L2)
4) Extend leg at knee joint, steadies hip joint and helps iliopsoas flex thigh

Question 7

Vastus lateralis

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 7

1) Greater trochanter and lateral lip of linea aspera of femur
2) Quadriceps tendon and independent attachments to base of patella, tibial tuberosity via patellar ligament, tibia and patella via aponeuroses (lateral patellar retinacula)
3) Femoral nerve (L3, L4, some L2)
4) Extend leg at knee joint

Question 8

Vastus medialis

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 8

1) Intertrochanteric line and medial lip of linea aspera of femur
2) Quadriceps tendon and independent attachments to base of patella, tibial tuberosity via patellar ligament, tibia and patella via aponeuroses (medial patellar retinacula)
3) Femoral nerve (L3, L4, some L2)
4) Extend leg at knee joint

Question 9

Vastus Intermedius

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 9

1) Anterior and lateral surfaces of shaft of femur
2) Quadriceps tendon and independent attachments to base of patella, tibial tuberosity via patellar ligament
3) Femoral nerve (L3, L4, some L2)
4) Extend leg at knee joint

Question 10

Adductor longus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 10

1) Body of pubis inferior to pubic crest
2) Middle third of linea aspera of femur
3) Obturator nerve (anterior, L3, some L2 and L4)
4) Adducts thigh

Question 11

Adductor brevis

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 11

1) Body and inferior ramus of pubis
2) Pectineal line and proximal part of linea aspera of femur
3) Obturator nerve (anterior, L3, some L2 and L4)
4) Adducts thigh, to some extent flexes it

Question 12

Adductor Magnus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 12

1) Adductor part: inferior ramus of pubis, ramus of ischium
Hamstrings part: ischial tuberosity
2) Adductor part: gluteal tuberosity, linea aspera, medial supracondylar line
Hamstring part: Adductor tubercle of femur
3) Adductor part: Obturator nerve (L3, L4, some L2), branches of posterior division
Hamstring part: tibial part of sciatic nerve (L4)
4) Adduct thigh, adductor part flexes thigh, hamstrings part extends thigh

Question 13

Gracilis

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 13

1) Body and inferior ramus of pubis
2) Superior part of medial surface of tibia
3) Obturator nerve (L2, some L3)
4) Adducts thigh; flexes leg; helps rotate leg medially

Question 14

Obturator externus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 14

1) Margins of obturator foramen and obturator membrane
2) Trochanteric fossa of femur
3) Obturator nerve (L4, some L3)
4) Laterally rotates thigh; steadies head of femur in acetabulum

Question 15

Tensor fasciae latae

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 15

1) Anterior superior iliac spine; anterior part of iliac crest
2) Iliotibial tract, which attaches to lateral condyle of tibia
3) Superior gluteal nerve (L5, S1)
4) Abduct and medially rotate thigh; keep pelvis level when ipsilateral limb is weight-bearing and advance opposite (unsupported) side during its swing phase

Question 16

Gluteus Maximus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 16

1) Ilium posterior to posterior gluteal line; dorsal surface of sacrum and coccyx; sacrotuberous ligament
2) Iliotibial tract/lateral condyle of tibia, gluteal tuberosity
3) Inferior gluetal nerve (S1 and S2, some L5)
4) Extends thigh (especially from flexed position) and assists in its lateral rotation; steadies thigh and assists in rising from sitting position

Question 17

Gluteus Medius

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 17

1) External surface of ilium between anterior and posterior gluteal lines
2) Lateral surface of greater trochanter of femur
3) Superior gluteal nerve (L5, some S1)
4) Abduct and medially rotate thigh; keep pelvis level when ipsilateral limb is weight-bearing and advance opposite (unsupported) side during its swing phase

Question 18

Gluteus Minimus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 18

1) External surface of ilium between anterior and inferior gluteal lines
2) Anterior surface of greater trochanter of femur
3) Superior Gluteal nerve
4) Abduct and medially rotate thigh; keep pelvis level when ipsilateral limb is weight-bearing and advance opposite (unsupported) side during its swing phase

Question 19

Piriformis

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 19

1) Anterior surface of sacrum; sacrotuberous ligament
2) Superior border of greater trochanter of femur
3) Branches of anterior rami of S1 (and some S2)
4) Laterally rotate extended thigh and abduct flexed thigh; steady femoral head in acetabulum

Question 20

Obturator internus

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 20

1) Pelvic surface of obturator membrane and surrounding bones
2) Medial surface of greater trochanter of femur (trochanteric fossa)
3) Nerve to obturator internus (S1, some L5)
4) Laterally rotate extended thigh and abduct flexed thigh; steady femoral head in acetabulum

Question 21

Superior and inferior gemelli

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 21

1) Superior: Ischial spine
Inferior: ischial tuberosity
2) Medial surface of greater trochanter (trochanteric fossa) of femur
3) Superior gemellus: same nerve supply as obturator internus (Nerve to obturator internus, S1, some L5)
4) Laterally rotate extended thigh and abduct flexed thigh; steady femoral head in acetabulum

Question 22

Quadratus femoris

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 22

1) Lateral border of ischial tuberosity
2) Quadrate tubercle on intertrochanteric crest of femur and area inferior to it
3) Nerve to quadratus femoris
4) Laterally rotates thigh; steadies femoral head in acetabulum

Question 23

Abductor hallucis

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 23

1) Medial process of the calcaneal tuberosity, plantar aponeurosis, flexor retinaculum
2) Base of the proximal phalanx of the great toe via the medial sesamoid
3) Medial plantar nerve (S1, S2)
4) flexion and medial abduction of the great toe, supports the longitudinal arch

Question 24

Flexor hallucis brevis

1) Origin
2) Insertion
3) Innervation
4) Action

Answer 24

1) Cuboid, lateral cuneiform
2) Medial head: base of the proximal phalanx of the great toe via the medial sesamoid
Lateral head: base of the proximal phalanx of the great toe via the lateral sesamoid
3) Medial plantar nerve (S1, S2)
4) Flexes the first metatarsophalangeal joint, supports the longitudinal arch

Question 25

Adductor hallucis 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 25

1) Oblique head: bases of the second through fourth metatarsals, cuboid, lateral cuneiform Transverse head: metatarsophalangeal joints of the third through fifth toes, deep transverse metatarsal ligament 2) Base of the first proximal phalanx by a common tendon via the lateral sesamoid 3) Lateral Plantar nerve (S2, S3) 4) Flexes the first metatarsophalangeal joint, adducts the great toe; transverse head supports the transverse arch, oblique head supports the longitudinal arch

Question 26

Abductor digiti minimi 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 26

1) Lateral process and inferior surface of the calcaneal tuberosity, plantar aponeurosis 2) Base of the proximal phalanx of the little toe, tuberosity of the fifth metatarsal 3) Lateral plantar nerve (S1-S3) 4) Flexes the metatarsophalangeal joint of the little toe, abducts little toe, supports the longitudinal arch

Question 27

Flexor digiti minimi brevis 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 27

1) Base of the fifth metatarsal, long plantar ligament 2) Base of the proximal phalanx of the little toe 3) Lateral plantar nerve (S2, S3) 4) Flexes the metatarsophalangeal joint of the little toe

Question 28

Opponens digiti minimi 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 28

1) Long plantar ligament, plantar tendon sheath of the fibularis longus 2) Fifth metatarsal 3) Lateral plantar nerve (S2, S3) 4) Pulls the fifth metatarsal slightly in the plantar and medial direction

Question 29

Flexor digitorum brevis 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 29

1) Medial tubercle of the calcaneal tuberosity, plantar aponeurosis 2) Sides of the middle phalanges of the second through fifth toes 3) Medial plantar nerve (S1, S2) 4) flexes the metatarsophalangeal and proximal interphalangeal joints of the second through fifth toes, supports the longitudinal arch of the foot

Question 30

Quadratus plantae 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 30

1) Medial and plantar borders on the plantar side of the calcaneal tuberosity 2) Lateral border of the flexor digitorum longus tendon 3) Lateral plantar nerve (S1-S3) 4) Redirects and augments the pull of the flexor digitorum longus

Question 31

Lumbricals 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 31

(There are four) 1) Medial borders of the flexor digitorum longus tendon 2) Dorsal aponeuroses of the second through fifth toes 3) First lumbrical: Medial plantar nerve (S2, S3) Second through fourth lumbricals: Lateral plantar nerve (S2, S3) 4) Flexes the metatarsophalangeal joints of the second through fifth toes Extension of the interphalangeal joints of the second through fifth toes Moves the toes closer together (adducts the 2nd through 5th toes towards the great toe)

Question 32

Dorsal interossei 1) Origin 2) Insertion 3) Innervation 4) Action

Answer 32

There are four 1) By two head from opposing sides of the 1st through 5th metatarsals 2) 1st interosseus: Medial base of the second proximal phalanx, dorsal aponeurosis of the second toe 2nd-4th: lateral base of the second through fourth proximal phalanges, dorsal aponeurosis of the 2nd through 4th toes 3) Lateral plantar nerve (S2, S3) 4) Flexes the metatarsophalangeal joints of the second through fourth toes and spreads the toes apart (abducts the third and fourth toes from the second toe)