Leg

Question 1

What forms the superolateral boundary of the popliteal fossa?

Answer 1

Biceps femoris

Question 2

What forms the superomedial boundary of the popliteal fossa?

Answer 2

Semitendinosous and Semimembranosous

Question 3

What forms the inferior boundaries of the popliteal fossa?

Answer 3

Medial and lateral heads of gastrocnemius

Question 4

What forms the roof and floor of the popliteal fossa?

Answer 4

Roof: Fascia lata
- Floor: Intercondylar area of femur, posterior joint capsule, popliteus muscle

Question 5

What is the order of neurovascular structures in the popliteal fossa (medial to lateral)?

Answer 5

Popliteal artery → popliteal vein → tibial nerve

Question 6

Which nerves pass through the popliteal fossa?

Answer 6

Tibial nerve, common fibular nerve, posterior cutaneous nerve of thigh

Question 7

What vein and lymphatic structures are found in the popliteal fossa?

Answer 7

Terminal small saphenous vein, lymph nodes

Question 8

What is the “screw home mechanism”?

Answer 8

Passive locking of the knee during last 30° of extension

Question 9

What causes the knee to lock in full extension?

Answer 9

Medial rotation of femur on tibia due to larger medial condyle

Question 10

What muscles maintain the locked knee position?

Answer 10

Vastus medialis, gluteus maximus, tensor fascia lata (via IT band)

Question 11

What muscle unlocks the knee?

Answer 11

Popliteus (tibial nerve, L4-S1)

Question 12

How does the popliteus unlock the knee?

Answer 12

Laterally rotates femur on fixed tibia

Question 13

What other muscles contribute to knee rotation?

Answer 13

Pes anserinus – medial rotation of tibia
- Biceps femoris – lateral rotation of tibia

Question 14

What muscles are in the superficial posterior compartment?

Answer 14

Gastrocnemius, Soleus, Plantaris

Question 15

What nerve innervates these muscles?

Answer 15

Tibial nerve (S1, S2)

Question 16

What is the “triceps surae”?

Answer 16

Gastrocnemius + Soleus (+ sometimes Plantaris)

Question 17

What is the function of triceps surae?

Answer 17

Push body forward & raise heel during walking/standing

Question 18

Where does the calcaneal tendon insert?

Answer 18

Posterior surface of the calcaneus

Question 19

What is the weakest point of the Achilles tendon?

Answer 19

Middle third (due to poor vascularity)

Question 20

What can cause Achilles tendon rupture?

Answer 20

Fluoroquinolones, corticosteroids, dialysis

Question 21

What is the Thompson test?

Answer 21

Calf squeeze test – no foot movement = Achilles rupture

Question 22

Which nerve supplies the deep posterior muscles?

Answer 22

Tibial nerve

Question 23

What is the function of flexor hallucis longus?

Answer 23

Flexes hallux, supports medial arch

Question 24

What is the function of flexor digitorum longus?

Answer 24

Flexes toes, supports both arches

Question 25

What is the primary function of tibialis posterior?

Answer 25

Inverts foot, supports medial longitudinal arch

Question 26

Which nerve supplies the anterior compartment?

Answer 26

Deep fibular nerve

Question 27

What does tibialis anterior do?

Answer 27

Inverts and dorsiflexes foot, supports medial arch

Question 28

What does extensor hallucis longus do?

Answer 28

Extends big toe

Question 29

What does extensor digitorum longus do?

Answer 29

Extends toes

Question 30

What does fibularis tertius do?

Answer 30

Dorsiflexes and everts foot

Question 31

What nerve supplies the lateral compartment?

Answer 31

Superficial fibular nerve

Question 32

What do fibularis longus & brevis do?

Answer 32

- Evert & plantarflex foot - Longus supports lateral arch

Question 33

What is the sural nerve and its function?

Answer 33

- Sensory nerve from tibial + common fibular - Supplies skin of posterolateral leg & lateral foot

Question 34

What is the course of the small saphenous vein?

Answer 34

- Arises from lateral dorsal venous arch, pierces fascia between gastrocnemius heads, drains into popliteal vein

Question 35

What spinal roots are tested in the Achilles reflex?

Answer 35

S1 and S2

Question 36

What is compartment syndrome?

Answer 36

Increased pressure in a leg compartment, can be acute (emergency) or chronic

Question 37

What are the 5 Ps of compartment syndrome?

Answer 37

Pain, Pallor, Paralysis, Pulselessness, Paresthesia