Lecture 16: Muscular System Lower Limb

Question 1

Muscles of gluteal region

Answer 1

2 groups
Superficial - mainly extensor and abductor of hip (gluteal maximus
Deep - lateral rotation of hip (piriformis)
Innervated by sacral plexus

Question 2

Gluteal maximus

Answer 2

Superficial group of gluteal region
Largest muscles of gluteal region
Origin: hip bone and sacrum
Insertion: greater trochanter of femur or lateral condyle of tibia via iliotibial band (dense connective tissue, thickening of deep fascia of thigh - fascia lata)
Function: prime mover for hip extension, stabilizes knee in full extension
Nerve: inferior gluteal nerve of sacral plexus

Question 3

Piriformis

Answer 3

Deep group of gluteal muscle
Origin: anterior surface of sacrum
Insertion: greater trochanter of femur
Function: lateral rotation of hip
Nerve: branch of sacral plexus

Question 4

Muscles of thigh

Answer 4

3 compartments
Anterior: extensor of knee joint, innervated by femoral nerve (iliopsoas, quadriceps femoris)
Medial: adductor of hip, innervated by obturator nerve (adductor magnus)
Posterior: hamstrings, flexors of knee joint, innervated by sciatic nerve (biceps femoris)
Made by femur and extensions of deep fascia of thigh attaching to femur

Question 5

Iliopsoas

Answer 5

Anterior compartment of thigh
Combination of psoas major and iliacus
Psoas major origin: lumbar vertebrae
Iliacus origin: iliac fossa of hip bone
Insertion: both origins merge to lesser trochanter of femur
Function: prime mover for flexion of hip
Nerve: lumbar plexus

Question 6

Quadriceps femoris

Answer 6

Anterior compartment of thigh
4 heads
Origin: either from hip bone or shaft of femur
Insertion: directly to patella, or indirectly to tibial tuberosity via patellar ligament
Function: prime mover for extension of knee
Nerve: femoral nerve

Question 7

Adductor magnus

Answer 7

Medial compartment of thigh
Origin: pubic bone and ischium
Insertion: linea aspera or adductor tubercle of femur (contains opening between insertions - adductor hiatus - for femoral artery and vein)
Function: prime mover for adduction of hip
Nerve: obturator and sciatic nerve

Question 8

Biceps femoris

Answer 8

Posterior compartment of thigh
Origin: ischial tuberosity and shaft of femur
Insertion: head of fibula
Function: extension of hip joint, and prime mover for flexion of knee joint
Nerve: sciatic nerve

Question 9

Muscles of leg

Answer 9

3 compartments
Anterior: dorsi flexors of ankle joint, extensors of toe, inverters of foot, innervated by deep fibular nerve (tibialis anterior)
Posterior: divided into superior - plantar flexors of ankle (gastrocnemius), and deep - flexors of toes (tibialis posterior); innervated by tibial nerve
Lateral: evertor of ankle joint, innervated by superficial fibular nerve (fibularis/peroneus longus)
Made by tibia, fibula, interosseous membrane, extensions of deep fascia of leg attaching to fibula

Question 10

Tibialis anterior

Answer 10

Anterior compartment of leg
Origin: lateral tibial condyle
Insertion: medial cuneiform (tarsal bone)
Function: prime mover for dorsi flexion and inversion
Nerve: deep fibular nerve

Question 11

Gastrocnemius

Answer 11

Superficial group of posterior compartment of leg
Origin: lateral and medial femoral condyle
Insertion: calcaneus tarsal bone via calcaneal tendon (achilles)
Function: flexion of knee and plantar flexion
Nerve: tibial nerve

Question 12

Tibialis posterior

Answer 12

Deep group of posterior compartment of leg
Origin: tibia, fibula, interosseous membrane
Insertion: all tarsal bones except talus
Function: plantar flexion, and maintains arch of foot
Nerve: tibial nerve

Question 13

FIbularis/peroneus longus

Answer 13

Lateral compartment of leg
Origin: shaft of fibula
Insertion: medial cuneiform
Function: prime mover for eversion of foot
Nerve: superficial fibular nerve

Question 14

Intrinsic muscles of foot on dorsal aspect

Answer 14

Extensor digitorum brevis
Extensor hallucis brevis
Function: extension of toes

Question 15

Intrinsic muscles of foot on plantar aspect - 1st layer

Answer 15

Function: abduct 1st or 5th toes, or flex lateral 4 toes
Nerve: tibial nerve

Question 16

Intrinsic muscles of foot on plantar aspect - 2nd layer

Answer 16

Function: flex lateral 4 toes
Has 2 tendons (flexor hallucis longus and flexor digitorum longus)
Nerve: tibial nerve

Question 17

Intrinsic muscles of foot on plantar aspect - 3rd layer

Answer 17

Function: flex 1st or 5th toes, or adduct first toe
Nerve: tibial nerve

Question 18

Intrinsic muscles of foot on plantar aspect - 4th layer

Answer 18

Function: abduct/adduct toes

Has 2 tendons

Question 19

Plantar aponeurosis

Answer 19

Thickening of deep fascia on sole of foot

Protects soft tissue and maintains foot arch

Question 20

Transitional areas of lower limb

Answer 20

Femoral triangle
Popliteal fossa
Tarsal tunnel

Question 21

Femoral triangle

Answer 21

Anterior aspect of thigh
Formed by inguinal ligament, sartorius muscle, adductor longus muscle
Contains: femoral vein, artery, nerve
Apex points inferiorly continuous with adductor canal and opens to popliteal fossa via adductor hiatus

Question 22

Popliteal fossa

Answer 22

Diamond shaped behind knee joint
Formed by hamstring muscles, lateral and medial heads of gastrocnemius
Contains popliteal artery and vein, tibial and common fibular nerve

Question 23

Tarsal tunnel

Answer 23

From medial malleolus and thickening of flexor retinaculum medial to ankle
Contains tendons of deep muscles of posterior compartment of leg, tibial nerve, posterior tibial artery and vein