Lower Leg Muscles - Posterior Compartment

Question 1

Superficial Muscles

Answer 1

• Gastrocnemius m.
• Soleus m.
• Plantaris m.

Question 2

Gastrocnemius m. - origin

Answer 2

Lateral head: lateral aspect of lateral condyle of femur

Medial head: popliteal surface of femur; superior to medial condyle

Question 3

Gastrocnemius m., Soleus m., Plantaris m. - insertion

Answer 3

Posterior surface of calcaneous via calcaneal tendon

Question 4

Gastrocnemius m., Soleus m., Plantaris m. - nerve

Answer 4

Tibial n. (S1, 2)

Question 5

Gastrocnemius m. - action

Answer 5

• PF ankle when knee extended
• Raise heel during walking
• Flex leg at knee joint

Question 6

Gastrocnemius m. - blood supply

Answer 6

Sural a., Posterior tibial a.

Question 7

Soleus m. - origin

Answer 7

• Posterior aspect of head and superior 1/4 of posterior fibula
• soleal line and middle 1/3 medial border of tibia
• tendinous arch extending b/t bony attachments

Question 8

Soleus m. - action

Answer 8

• PF ankle independent of position of knee

- Steadies leg on foot

Question 9

Soleus m. - blood supply

Answer 9

Popliteal a., posterior tibial a., fibular a.

Question 10

Plantaris m. - origin

Answer 10

• Inferior end of lateral supracondylar line of femur

- Oblique popliteal ligament

Question 11

Plantaris m. - action

Answer 11

Weakly assist gastroc in PF ankle

Question 12

Plantaris m. - blood supply

Answer 12

Sural a., popliteal a., superior lateral genicular a.

Question 13

Deep Muscles

Answer 13

• Popliteus m.
• Flexor hallucis longus m.
• Flexor digitorum longus m.
• Tibialis posterior m.

Question 14

Popliteus m. - origin

Answer 14

Lateral surface of lateral condyle of femur and lateral meniscus

Question 15

Popliteus m. - insertion

Answer 15

Posterior surface of tibia and superior to soleal line

Question 16

Popliteus m. - nerve

Answer 16

Tibial n. (L4,5, S1)

Question 17

Popliteus m. - action

Answer 17

• Weakly flex knee
• Unlocks femur by rotating femur 5” on fixed tibia
• IR tibia of unplanted limb

Question 18

Popliteus m. - blood supply

Answer 18

Inferior medial genicular a., inferior lateral genicular a.

Question 19

Flexor hallucis longus m. - origin

Answer 19

• Inferior 2/3 posterior surface of fibula

- Inferior part of interosseous membrane

Question 20

Flexor hallucis longus m. - insertion

Answer 20

Base of dorsal phalanx of great toe

Question 21

Flexor hallucis longus m., Flexor digitorum longus m. - nerve

Answer 21

Tibial n. (S2, 3)

Question 22

Flexor hallucis longus m. - action

Answer 22

• Flex great toe at all joints
• Weak PF of ankle
• Supports medial longitudinal arch of foot

Question 23

Flexor hallucis longus m. - blood supply

Answer 23

Fibular a.

Question 24

Flexor digitorum longus m. - origin

Answer 24

Medial part of posterior surface of tibia inferior to soleal line by broad tendon to fibula

Question 25

Flexor digitorum longus m. - insertion

Answer 25

Bases of distal phalanges of lateral 4 digits

Question 26

Flexor digitorum longus m. - action

Answer 26

• Flex lateral 4 digits
• PF ankle
• Supports longitudinal arches of foot

Question 27

Flexor digitorum longus m. - blood supply

Answer 27

Posterior tibial a.

Question 28

Tibialis posterior m. - origin

Answer 28

• Interosseous membrane
• Posterior surface of tibia inferior to soleal line
• Posterior surface of fibula

Question 29

Tibialis posterior m. - insertion

Answer 29

• Tuberosity of navivular, cuneiform, cuboid, and sustentaculum tali of calcaneus
• Base of MT 2,3,4

Question 30

Tibialis posterior m. - nerve

Answer 30

Tibial n. (L4,5)

Question 31

Tibialis posterior m. - action

Answer 31

• PF ankle

- Invert foot

Question 32

Tibialis posterior m. - blood supply

Answer 32

Fibular a., Posterior tibial a.