Module 5.2 Part 2 - Muscles of Lower Extremities

Question 1

Psoas major

Answer 1

Origin: transverse bodies of all lumbar vertebrae
Insertion: lesser trochanter of the femur (with Iliacus)
Action: hip flexion or trunk flexion (if femur is stationary)
Innervation: lumbar plexus

Question 2

Iliacus

Answer 2

Origin: iliac fossa of ilium
Insertion: lesser trochanter of femur
Action: hip flexion
Innervation: femoral nerve

Question 3

Gluteus Maximus

Answer 3

Origin: posterior gluteal line of the ilium, lower sacrum, side of coccyx
Insertion: gluteal tuberosity
Action: abducts, extends, and laterally rotates hip joint
Innervation: inferior gluteal nerve

Question 4

Gluteus Medius

Answer 4

Origin: gluteal surface of ilium
Insertion: greater trochanter of femur
Action: abducts thigh, stabilizes hip joint
Innervation: superior gluteal nerve

Question 5

Gluteus Minimus

Answer 5

Origin: gluteal surface of ilium
Insertion: greater trochanter of femur
Action: abducts thigh, stabilizes hip joint
Innervation: superior gluteal nerve

Question 6

TFL - Tensor Fascia Latae

Answer 6

Origin: ASIS
Insertion: iliotibial tract
Action: abducts and internally rotates thigh, stabilizes hip and knee joints
Innervation: superior gluteal nerve

Question 7

Obterator Externus

Answer 7

Action: lateral rotation of thigh
Innervation: obterator nerve

Question 8

Obterator Internus

Answer 8

Action: lateral rotation of thigh
Innervation: spinal nerves S1-3

Question 9

Superior Gemellus

Answer 9

Action: lateral rotation, adduction, and extension at hip joint
Innervation: spinal nerves L5 and S1

Question 10

Inferior Gemellus

Answer 10

Action: lateral rotation, adduction, and extension at hip joint
Innervation: spinal nerves L5 and S1

Question 11

Quadratus Femoris

Answer 11

Action: lateral rotation and adduction of hip joint
Innervation: spinal nerves L5 and S1

Question 12

Piriformis

Answer 12

Action: lateral rotation, adduction, and extension of hip joint
Innervation: spinal nerves L5 -S2

Question 13

Biceps Femoris

Answer 13

Origin: Long head - ischial tuberosity; short head - linea aspera of femur, lateral surface
Insertion: head of the fibula and lateral surface
Action: knee flexion, hip extension
Innervation: Long head - tibial nerve; Short head - common fibular nerve

Question 14

Semitendinosus

Answer 14

Origin: ischial tuberosity
Insertion: medial surface of tibia
Action: knee flexion
Innervation: tibial nerve

Question 15

Semimembranosus

Answer 15

Origin: ischial tuberosity
Insertion: medial condyle of tibia
Action: knee flexion
Innervation: tibial nerve

Question 16

Rectus Femoris

Answer 16

Origin: AIIS
Insertion: common tendon of quadriceps to tibial tuberosity
Action: knee extension, hip flexion
Innervation: femoral nerve

Question 17

Vastus Medialis

Answer 17

Origin: intertrochanteric line of femur
Insertion: patella via quadriceps tendon, tibial tuberosity
Action: knee extension
Innervation: femoral nerve

Question 18

Vastus Lateralus

Answer 18

Origin: greater trochanter of femur
Insertion: patella via quadriceps tendon, tibial tuberosity
Action: knee extension
Innervation: femoral nerve

Question 19

Vastus Intermedius

Answer 19

Origin: anterior/lateral surfaces of femur
Insertion: common tendon of quadriceps to tibial tuberosity
Action: knee extension
Innervation: femoral nerve

Question 20

Adductor Longus

Answer 20

Origin: front of pubis
Insertion: linea aspera
Action: adducts, mediallly rotates thigh
Innervation: obturator nerve

Question 21

Adductor Brevis

Answer 21

Origin: superior and inferior rami of pubis
Insertion: medial shaft of femur, into upper linea aspera
Action: adducts, medially rotates thigh
Innervation: obterator nerve

Question 22

Adductor Magnus

Answer 22

Origin: inferior ramus of pubis
Insertion: adductor tubercle, medial condyle of femur, linea aspera
Action: adducts, medially rotates thigh
Innervation: obterator nerve

Question 23

Gracilis

Answer 23

Origin: lower half of pubic symphysis
Insertion: superior shaft of tibia
Action: adductor of thigh, flexes knee
Innervation: obturator nerve

Question 24

Pectinieus

Answer 24

Origin: pectineal line
Insertion: posterior surface of femur
Action: adducts thigh
Innervation: femoral nerve

Question 25

Sartorius

Answer 25

Origin: ASIS Insertion: superior shaft of tibia Action: hip flexion, abduction, external rotation; knee flexion, internal rotation Innervation: femoral nerve

Question 26

Tibialis Anterior

Answer 26

Origin: lateral condyle of tibia Insertion: base of 1st metatarsal, medial cunieform Action: dorsiflexion, inversion of foot Innervation: deep peroneal nerve

Question 27

Extensor Digitorum Longus

Answer 27

Origin: lateral condyle of fibula Insertion: distal phalanges of digits 2-5 Action: extends digits 2-5, dorsiflexion of foot Innervation: deep peroneal nerve

Question 28

Extensor Hallucis Longus

Answer 28

Origin: anterior surface of fibula Insertion: dorsal surface of digit 1 (great toe) Action: extension of digit 1 and dorsiflexion of foot Innervation: deep peroneal nerve

Question 29

Peroneus Brevis

Answer 29

Origin: lateral, distal fibula Insertion: lateral side of 5th metatarsal Action: plantarflex and evert (pronate) foot Innervation: superficial peroneal nerve

Question 30

Peroneus Longus

Answer 30

Origin: posterior surface of tibia, superior fibula Insertion: base of metatarsal 1 Action: plantarflex and evert (pronate) foot Innervation: superficial peroneal nerve

Question 31

Gastrocnemius

Answer 31

Origin: medial and lateral heads - posterior surfaces of medial and lateral femoral condyles Insertion: posterior surface of calcaneous via achilles tendon Action: plantarflexion of foot, knee flexion Innervation: tibial nerve

Question 32

Soleus

Answer 32

Origin: posterior surface of fibula, medial region of posterior tibia Insertion: posterior surface of calcaneous via the achilles tendon Action: plantar flexion of foot Innervation: tibial nerve

Question 33

Tibialis Posterior

Answer 33

Origin: posterior surface of tibia, interroseous membrane, medial surface of fibula Insertion: navicular bone, cunieforms(3), cuboid, and metatarsals 2-4 Action: plantarflexion, inversion and adduction of foot Innervation: tibial nerve

Question 34

Flexor Digitorum Longus

Answer 34

Origin: posterior surface of tibia Insertion: inferior surface of distal phalanges 2-5 Action: flexion of digits 2-5, inversion and plantarflexion of foot Innervation: deep peroneal nerve

Question 35

Flexor Hallucis Longus

Answer 35

Origin: posterior fibula Insertion: inferior surface of distal phalanx of digit 1 (great toe) Action: flexion of digit 1, inversion and plantar flexion of foot Innervation: tibial nerve (deep peroneal branch)