muscle details of lower body

Question 1

Gluteus maximus
(origin/insertion/innervation/action/blood supply)

Answer 1

• Origin
  Lateroposterior surface of sacrum and coccyx, gluteal surface of ilium, thoracolumbar fascia, Sacrotuberous ligament
• Insertion
  Iliotibial tract, gluteal tuberosity of femur
• Action
  Hip joint: Thigh extension, thigh external rotation, thigh abduction (superior part), thigh adduction (inferior part)
• Innervation
  Inferior gluteal nerve (L5, S1, S2)
• Blood supply
  Inferior gluteal and superior gluteal arteries

Question 2

Gluteus medius
(origin/insertion/innervation/action/blood supply)

Answer 2

• Origin
  Gluteal surface of ilium
• Insertion
  Lateral aspect of greater trochanter of femur
• Action
  Hip joint: Thigh abduction, thigh internal rotation (anterior part); Pelvis stabilization
• Innervation
  Superior gluteal nerve (L4-S1)
• Blood supply
  Deep branch of superior gluteal artery, trochanteric anastomosis

Question 3

gluteus minimus
(origin/insertion/innervation/action/blood supply)

Answer 3

• Origin
  Gluteal surface of ilium
• Insertion
  Anterior aspect of greater trochanter of femur
• Action
  Hip joint: Thigh abduction, thigh internal rotation (anterior part); Pelvis stabilization
• Innervation
  Superior gluteal nerve (L4-S1)
• Blood supply
  Superior gluteal artery, trochanteric anastomosis

Question 4

piriformis
(origin/insertion/innervation/action/blood supply)

Answer 4

• Origin
  Anterior surface of the sacrum, Gluteal surface of ilium
• Insertion
  Greater trochanter of the femur
• Action
  Hip joint: Thigh external rotation, Thigh abduction; Stabilizes head of femur in acetabulum
• Innervation
  Nerve to piriformis (S1-S2)
• Blood supply
  Superior gluteal artery, inferior gluteal artery, gemellar branches of the internal pudendal

Question 5

gemellus superior
(origin/insertion/innervation/action/blood supply)

Answer 5

• Origin
  Ischial spine
• Insertion
  Medial surface of greater trochanter of femur (tendon of obturator internus)
• Action
  Hip joint: Thigh external rotation, thigh abduction ; stabilizes head of femur in acetabulum
• Innervation
  Nerve to obturator internus (L5-S1)
• Blood supply
  Internal pudendal artery, inferior gluteal artery

Question 6

gemellus inferior
(origin/insertion/innervation/action/blood supply)

Answer 6

• Origin
  Ischial tuberosity
• Insertion
  Medial surface of greater trochanter of femur (tendon of obturator internus)
• Action
  Hip joint: Thigh external rotation, thigh abduction, stabilizes head of femur in acetabulum
• Innervation
  Nerve to quadratus femoris (L4/5, S1)
• Blood supply
  Medial circumflex femoral artery

Question 7

obturator internus
(origin/insertion/innervation/action/blood supply)

Answer 7

• Origin
  Posterior surface of the obturator membrane; bony boundaries of the obturator foramen
• Insertion
  Medial surface of greater trochanter of femur
• Action
  External rotation of extended thigh
  Abduction of flexed thigh;
  Stabilization of hip joint
• Innervation
  Nerve to obturator internus (L5 and S1)
• Blood supply
  Obturator artery; internal pudendal artery

Question 8

obturator externus
(origin/insertion/innervation/action/blood supply)

Answer 8

• Origin
  Anterior surface of obturator membrane, bony boundaries of obturator foramen
• Insertion
  Trochanteric fossa of femur
• Action
  Hip joint: Thigh external rotation, thigh abduction (from flexed hip); Stabilizes head of femur in acetabulum
• innervation
  Obturator nerve (L3, L4)
• Blood supply
  Obturator and medial circumflex femoral arteries.

Question 9

quadratus femori
(origin/insertion/innervation/action/blood supply)

Answer 9

• Origin
  Ischial tuberosity
• Insertion
  Intertrochanteric crest of femur
• Action
  Hip joint: thigh external rotation; stabilizes head of femur in acetabulum
• Innervation
  Nerve to quadratus femoris (L4-S1)
• Blood supply
  Inferior gluteal artery

Question 10

ileopsoas major
(origin/insertion/innervation/action/blood supply)

Answer 10

• Origin
  Vertebral bodies of T12-L4, transverse processes of L1-L5 vertebrae
• Insertion
  Lesser trochanter of femur as iliopsoas tendon
• Action
  Hip joint: Flexion of the thigh/trunk, lateral rotation of the thigh
  Lateral flexion of the trunk
• Innervation
  Anterior rami of spinal nerves L1-L3
• Blood supply
  Lumbar branch of iliolumbar artery

Question 11

ileopsoas minor
(origin/insertion/innervation/action/blood supply)

Answer 11

• Origin
  Vertebral bodies of T12 & L1 vertebrae
• Insertion
  Iliopubic eminence, pecten pubis
• Blood supply
  Lumbar arteries
• Innervation
  Anterior ramus of spinal nerve L1
• Action
  Weak trunk flexion

Question 12

iliacus
(origin/insertion/innervation/action/blood supply)

Answer 12

• Origin
  Iliac fossa
• Insertion
  Lesser trochanter of femur
• Action
  Hip joint: Thigh/trunk flexion
• Innervation
  Femoral nerve (L1-L3)
• Blood supply
  Iliolumbar, deep circumflex iliac, obturator, and femoral arterie

Question 13

tensor fasciae latae
(origin/insertion/innervation/action/blood supply)

Answer 13

• Origin
  Outer lip of anterior iliac crest, Anterior superior iliac spine
• Insertion
  Lateral condyle of tibia (ileotibial tract)
• Action
  Hip joint: Thigh internal rotation
  Knee joint: Leg external rotation
  Stabilizes hip & knee joints
• Innervation
  Superior gluteal nerve (L4-S1)
• Blood supply
  Ascending branch of lateral circumflex femoral artery

Question 14

sartorius
(origin/insertion/innervation/action/blood supply)

Answer 14

• Origin
  Anterior superior iliac spine
• Insertion
  Proximal end of tibia below medial condyle (via pes anserinus)
• Innervation
  Femoral nerve (L2-L3)
• Blood supply
  Proximal third: branches of femoral artery, deep femoral artery, artery of quadriceps, lateral circumflex femoral artery
  Middle third: branches of femoral artery
  Distal third: branches of femoral and descending genicular arteries
• Function
  Hip joint: thigh flexion, thigh abduction, thigh external rotation
  Knee joint: leg flexion, leg internal rotation

Question 15

vastus lateralis
(origin/insertion/innervation/action/blood supply)

Answer 15

• origin
  Intertrochanteric line, greater trochanter, gluteal tuberosity, linea aspera of femur
• insertion
  Tibial tuberosity (via patellar ligament), patella, (lateral condyle of tibia)
• innervation
  Femoral nerve (L2-L4)

-action
Hip joint: Thigh flexion (rectus femoris only);
Knee joint: Leg extension

• blood supply
  ateral circumflex femoral and deep femoral arteries; artery to quadriceps

Question 16

vastus medialis
(origin/insertion/innervation/action/blood supply)

Answer 16

• origin
  Intertrochanteric line, pectineal line of femur, linea aspera, medial supracondylar line of femur
• insertion
  Tibial tuberosity (via patellar ligament), patella, (medial condyle of tibia)
• innervation
  Femoral nerve (L2-L4)

-action
Hip joint: Thigh flexion (rectus femoris only);
Knee joint: Leg extension

• blood supply
  Femoral, deep femoral, descending genicular artery

Question 17

rectus femoris
(origin/insertion/innervation/action/blood supply)

Answer 17

• origin
  Anterior inferior iliac spine, supraacetabular groove
• insertion
  Tibial tuberosity (via patellar ligament), patella
• innervation
  Femoral nerve (L2-L4)

-action
Hip joint: Thigh flexion (rectus femoris only);
Knee joint: Leg extension

• blood supply
  Femoral, lateral femoral circumflex, superficial circumflex iliac arteries

Question 18

vastus intermedius
(origin/insertion/innervation/action/blood supply)

Answer 18

• origin
  Anterior surface of femoral shaft

-insertion
Tibial tuberosity (via patellar ligament), patella

• innervation
  Femoral nerve (L2-L4)

-action
Hip joint: Thigh flexion (rectus femoris only);
Knee joint: Leg extension

• blood supply
  Artery to quadriceps, deep femoral arteries

Question 19

pectineus
(origin/insertion/innervation/action/blood supply)

Answer 19

• Origin
  Superior pubic ramus (pectineal line)
• Insertion
  Pectineal line of femur, linea aspera of femur
• Action
  Hip joint: Thigh flexion, thigh adduction, thigh external rotation, thigh
  internal rotation; pelvis stabilization
• Innervation
  Femoral nerve (L2, L3)
  (Obturator nerve (L2, L3))
• Blood supply
  Medial femoral circumflex artery, obturator artery

Question 20

adductor brevis
(origin/insertion/innervation/action/blood supply)

Answer 20

• Origin
  Anterior body of pubis, inferior pubic ramus
• Insertion
  Linea aspera of femur (medial lip)
• Action
  Hip joint: thigh flexion, thigh adduction, thigh external rotation; pelvis stabilization
• Innervation
  Obturator nerve (L2-L4)
• Blood supply
  Arteria profunda femoris

Question 21

adductor Magnus
(origin/insertion/innervation/action/blood supply)

Answer 21

-Origin
Adductor part: Inferior pubic ramus, ischial ramus
Ischiocondylar part: Ischial tuberosity

• Insertion
  Adductor part: Gluteal tuberosity, linea aspera (medial lip), medial supracondylar line
  Ischiocondylar part: Adductor tubercle of femur
• Action
  Adductor part:
  Hip joint - Thigh flexion, thigh adduction, thigh external rotation
  Hamstring part:
  Hip joint - Thigh extension, thigh internal rotation
  Entire muscle: Pelvis stabilization
• Innervation
  Adductor part: Obturator nerve (L2-L4)
  Ischiocondylar part: Tibial division of sciatic nerve (L4)
• Blood supply
  Deep femoral artery;
  Femoral, popliteal and genicular arteries

Question 22

adductor longs
(origin/insertion/innervation/action/blood supply)

Answer 22

• Origin
  Body of pubis, inferior to pubic crest and lateral to the pubic symphysis
• Insertion
  Middle third of linea aspera of femur (medial lip)
• Action
  Hip joint: Thigh flexion, Thigh adduction, Thigh external rotation; Pelvis stabilization
• Innervation
  Obturator nerve (L2-L4)
• Blood supply
  Deep femoral artery, obturator artery

Question 23

gracilis
(origin/insertion/innervation/action/blood supply)

Answer 23

• Origin
  Anterior body of pubis, inferior pubic ramus, ischial ramus
• Insertion
  Medial surface of proximal tibia (via pes anserinus)
• Actions
  Hip joint: Thigh flexion, thigh adduction;
  Knee joint: leg flexion, leg internal rotation
• Innervation
  Obturator nerve (L2-L3)
• Blood supply
  Deep femoral artery (via artery to the adductors)

Question 24

semimembranosus
(origin/insertion/innervation/action/blood supply)

Answer 24

• Origin
  Superolateral impression of ischial tuberosity
• Insertion
  Medial condyle of tibia
• Action
  Hip joint: thigh extension and internal rotation
  Knee joint: flexion and internal rotation of the leg
  Stabilizes pelvis
• Innervation
  Tibial division of sciatic nerve (L5 – S2)
• Blood supply
  Perforating branches of femoral and popliteal arteries

Question 25

semitendinosus
(origin/insertion/innervation/action/blood supply)

Answer 25

• Origin
  Ischial tuberosity
• Insertion
  Proximal end of tibia below medial condyle (via pes anserinus)
• Action
  Hip joint: Thigh extension, thigh internal rotation, stabilizes pelvis.
  Knee joint: Leg flexion, leg internal rotation.
• Innervation
  Tibial division of sciatic nerve (L5-S2)
• Blood supply
  First perforating branch of deep femoral artery, medial femoral circumflex artery, inferior gluteal artery and inferior medial geniculate artery

Question 26

bicep femori
(origin/insertion/innervation/action/blood supply)

Answer 26

• Origin
  Long head: ischial tuberosity, sacrotuberous ligament
  Short head: linea aspera of femur (lateral lip), lateral supracondylar line of femur
• Insertion
  (Lateral aspect of) head of fibula
• Action
  Hip joint: thigh extension, thigh external rotation;
  Knee joint: leg flexion, leg external rotation; stabilizes pelvis
• Innervation
  Long head: tibial division of sciatic nerve (L5-S2)
  Short head: common fibular division of sciatic nerve (L5-S2)
• Blood supply
  Inferior gluteal artery, perforating arteries, popliteal artery

Question 27

tibialis anterior muscle
(origin/insertion/innervation/action/blood supply)

Answer 27

• Origin
  Lateral surface of tibia
• Insertion
  Medial cuneiform bone, base of metatarsal bone 1
• Action
  Talocrural joint: foot dorsiflexion
  subtalar joint: foot inversion
• Innervation
  Deep fibular nerve (L4, L5)
• Blood supply
  Branches of anterior tibial artery
  Branches of posterior tibial artery

Question 28

extensor hallucis longus
(origin/insertion/innervation/action/blood supply)

Answer 28

• Origin
  Middle third of medial surface of fibula
• Insertion
  Base of distal phalanx of great toe
• Action
  toe extension; foot dorsiflexion
• Innervation
  Deep fibular nerve
• Blood supply
  Anterior tibial artery

Question 29

extensor digitorum longus
(origin/insertion/innervation/action/blood supply)

Answer 29

• Origin
  medial surface of fibula, lateral tibial condyle,
• Insertion
  Distal and middle phalanges of digits 2-5
• Action
  Toe extension; Foot dorsiflexion; Foot eversion
• Innervation
  Deep fibular nerve
• Blood supply
  Anterior tibial, fibular, anterior lateral malleolar, lateral tarsal, metatarsal, plantar, and digital arteries

Question 30

fibularis tertius
(origin/insertion/innervation/action/blood supply)

Answer 30

• Origin
  distal medial surface of fibula
• Insertion
  Dorsal surface of base of metatarsal bone 5
• Action
  Foot dorsiflexion, Foot eversion
• Innervation
  Deep fibular nerve (L5, S1)
• Blood supply
  Anterior lateral malleolar artery, lateral tarsal artery, metatarsal arteries, lateral plantar artery, digital arteries, arcuate artery, fourth dorsal metatarsal artery

Question 31

fibularis longus
(origin/insertion/innervation/action/blood supply)

Answer 31

• Origin
  Head of fibula, lateral surface of fibula
• Insertion
  Medial cuneiform bone, metatarsal bone 1
• Action
  Foot plantar flexion, Foot eversion;
  Supports longitudinal and transverse arches of foot
• Innervation
  Superficial fibular nerve (L5, S1)
• Blood supply
  Fibular artery

Question 32

fibularis brevis
(origin/insertion/innervation/action/blood supply)

Answer 32

• Origin
  Distal 2/3 of the lateral surface of fibula
• Insertion
  Tuberosity of the 5th metatarsal bone
• Action
  Foot plantar flexion, Foot eversion
• Innervation
  Superficial fibular nerve (L5, S1)
• Blood supply
  Anterior tibial artery

Question 33

gastrocnemius
(origin/insertion/innervation/action/blood supply)

Answer 33

• Origin
  -Lateral head: lateral condyle of the femur
  -Medial head: medial femoral condyle
• Insertion
  Posterior surface of the calcaneus via the calcaneal tendon
• Innervation
  Tibial nerve (S1, S2)
• Function
  Foot plantar flexion, Leg flexion

Question 34

soleus
(origin/insertion/innervation/action/blood supply)

Answer 34

• Origin
  Soleal line, medial border of tibia, head of fibula, posterior border of fibula
• Insertion
  Posterior surface of calcaneus (via calcaneal tendon)
• Innervation
  Tibial nerve (S1, S2)
• Vascularization
  Posterior tibial artery and vein
• Function
  Foot plantar flexion

Question 35

plantaris
(origin/insertion/innervation/action/blood supply)

Answer 35

• Origin
  Lateral supracondylar line of femur, oblique popliteal ligament of knee
• Insertion
• Posterior surface of calcaneus (via calcaneal tendon)
• Action
  foot plantar flexion
  knee flexion
• Innervation
  Tibial nerve (S1, S2)
• Blood supply
  lateral sural and popliteal arteries, superior lateral genicular artery

Question 36

tibialis posterior
(origin/insertion/innervation/action/blood supply)

Answer 36

• Origin
  Posterior surface of tibia, posterior surface of fibula and interosseous membrane
• Insertion
  Tuberosity of navicular bone, all cuneiform bones, cuboid bone, bases of metatarsal bones 2-4
• Actions
  Foot plantarflexion, Foot inversion, Supports medial longitudinal arch of foot
• Innervation
  Tibial nerve (L4, L5)
• Blood supply
  Branches of the posterior tibial artery

Question 37

flexor digitorum longus
(origin/insertion/innervation/action/blood supply)

Answer 37

• Origin
  Posterior surface of tibia
• Insertion
  Bases of distal phalanges of digits 2-5
• Action
  toe flexion, foot plantar flexion, foot inversion
• Innervation
  Tibial nerve (L5, S1, S2)
• Blood supply
• Posterior tibial artery

Question 38

Flexor hallucis longus
(origin/insertion/innervation/action/blood supply)

Answer 38

• Origin
  (Distal 2/3 of) Posterior surface of fibula
• Insertion
  Base of distal phalanx of great toe
• Innervation
  Tibial nerve (S2, S3)
• Function
  Toe flexion;Foot plantar flexion;Foot inversion
• Blood supply
  Posterior tibial artery, fibular artery

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Question 39

Popliteus
(origin/insertion/innervation/action/blood supply)

Answer 39

• Origin
  Lateral condyle of femur, posterior horn of lateral meniscus of knee joint
• Insertion
  Posterior surface of proximal tibia
• Innervation
  Tibial nerve (L4-S1)
• Blood supply
  popliteal artery, posterior tibial recurrent artery, posterior tibial artery, nutrient artery of tibia
• Function
  Unlocks knee joint; Knee joint stabilization