Posterior Leg: Part 1

Question 1

Fascial compartments of the leg formed by

Answer 1

• Tibia and fibula
• Intermuscular septa
• Interosseous membrane

Question 2

Anterior compartment

Answer 2

• Extensors of ankle (foot) and toes
• Deep fibular (peroneal) nerve
• Anterior tibial artery

Question 3

Posterior compartment

Answer 3

• Flexors of ankle and toes
• Tibal nerve
• Posterior tibial and fibular arteries

Question 4

Lateral compartment

Answer 4

• Evertors of ankle
• Superficial fibular nerve
• Perforating branches of anterior tibial and fibular arteries

Question 5

Small saphenous vein arises from

Answer 5

• Dorsal venous arch (lateral marginal vein)

- Dorsal vein of 5th digit

Question 6

Small saphenous vein pathway

Answer 6

• Posterior to lateral malleolus
• Drains into popliteal vein (not always)
• Travels with sural nerve

Question 7

Majority of superficial lymph vessels (in superficial fascia) drain into

Answer 7

• Vertical group of superficial inguinal nodes (great saphenous territory)

Question 8

Superficial lymphatics in the small saphenous territory (posterior, lateral leg and foot) drain into

Answer 8

• Popliteal nodes

Question 9

Deep lymphatics (deep to deep fascia)

Answer 9

• Lymph vessels travel with blood vessels and drain into:
• Popliteal nodes (deep tissues of leg and foot)
• Popliteal nodes drain into deep inguinal nodes

Question 10

Tibial nerve (L4-S3) gives off

Answer 10

• Medial sural cutaneous (S1,2)

Question 11

Common fibular (L4-S2) gives off

Answer 11

• Lateral sural cutaneous (L5-S2)

- Sural (fibular or peroneal) communicating branch (S1,2)

Question 12

Lateral sural cutaneous (L5-S2) supplies

Answer 12

• Superior lateral leg

Question 13

Sural nerve (S1,2) is formed by

Answer 13

• Fibular communicating branch joins medial sural cutaneous

Question 14

Sural nerve (S1,2) pathway

Answer 14

• Runs close to small saphenous vein

- Passes around posterior border of lateral malleolus than inferior to it

Question 15

Sural nerve (S1,2) supplies

Answer 15

• Distal posterior and lateral leg
• Lateral calcaneus (lateral calcaneal branches)
• Lateral side of foot and lateral side of 5th digits (lateral dorsal cutaneous nerve)

Question 16

Posterior compartment of leg (posterior crural compartment)

Answer 16

• 2 subcompartments
• Divided by deep transverse intermuscular septum of the leg (deep transverse crural intermuscular septum)
• Attach medial margin of tibia and posterior border of fibula

Question 17

Superficial compartment supplied by

Answer 17

• Sural arteries

Question 18

Deep compartment supplied by

Answer 18

• Posterior tibial arteries
• More tightly surrounded by fascia
• More susceptible to compartment syndrome

Question 19

Functions of posterior compartment muscles

Answer 19

• Tibial nerve supplies the muscle
• Plantarflexion (flexors)
• Inversion
• Toe flexion

Question 20

Tendons of posterior compartment muscles pathway

Answer 20

• Pass and insert medial to subtalar joint

- Can cause supination of the subtalar joint

Question 21

Primary functions of superficial muscles of the posterior compartment

Answer 21

• Powerful plantarflexors

Question 22

Muscles of the superficial posterior compartment

Answer 22

• Gastrocnemius
• Soleus
• Plantaris
• Calcaneal tendon (Achilles)

Question 23

Gastrocnemius

Answer 23

• 2 heads originate from femoral condyles

- Important in rapid, power movement

Question 24

Gastrocnemius medial head origin

Answer 24

• Posterior aspect of medial femoral condyle
• Inferior aspect of medial supracondylar line
• Crural fascia

Question 25

Gastrocnemius lateral head origin

Answer 25

- Posterior aspect of lateral femoral condyle - Inferior aspect of lateral supracondylar line - Crural fascia

Question 26

Gastrocnemius (both heads) insertion

Answer 26

- The 2 heads fuse and anchor to the gastrocnemius aponeurosis - The aponeurosis will join with superficial surface of soleus aponeurosis - Middle 1/3 of posterior surface of calcaneus (via calcaneal tendon/Achilles tendon/tendo calcaneus)

Question 27

Gastrocnemius innervation

Answer 27

- Tibial nerve

Question 28

Gastrocnemius blood supply

Answer 28

- Medial and lateral sural arteries | - End arteries

Question 29

Gastrocnemius function

Answer 29

- Plantarflexion foot (ankle) - Flexion of the leg - Subtalar supination

Question 30

Flabella

Answer 30

- Sesamoid bone in lateral head of gastrocnemius - ~10-30% of population - Studies have shown that it is getting more prevalant

Question 31

Soleus

Answer 31

- Broad/flat muscle - Forms soleal arch (tibial nerve/popliteal artery passes deep) - Continuously active

Question 32

Soleus origin

Answer 32

- Middle 1/3 of tibia medial border - Soleal line - Tendinous arch - Posterior aspect of fibular head - Proximal 1/3 of fibula

Question 33

Soleus insertion

Answer 33

- Joins with gastrocnemius | - Same as gastrocnemius

Question 34

Soleus innervation

Answer 34

- Tibial nerve

Question 35

Soleus blood supply

Answer 35

- Sural arteries - Fibular artery - Posterior tibial artery

Question 36

Soleus function

Answer 36

- Plantarflex foot (ankle)

Question 37

Triceps surae (gastroc-soleus group)

Answer 37

- Gastrocneumius + Soleus - 3 heads (share insertion) - Powerful plantarflexors

Question 38

Plantaris

Answer 38

- Small muscle | - Long tendon between gastrocnemius and soleus

Question 39

Plantaris origin

Answer 39

- Distal aspect lateral supracondylar line | - Travels inferomedially

Question 40

Plantaris insertion

Answer 40

- Medial aspect of middle 1/3 of posterior calcaneus | - Medial to achilles

Question 41

Plantaris innervation

Answer 41

- Tibial nurve

Question 42

Plantaris blood supply

Answer 42

- Sural artery

Question 43

Plantaris function

Answer 43

- Plantarflexion - Knee flexion - Probably proprioceptive function - Used in reconstructive surgery

Question 44

Gastrocnemius aponeurosis fuses with

Answer 44

- Soleal aponeurosis

Question 45

Calcaneal tendon (Achilles) inserts into

Answer 45

- Posterior calcaneus - Twists inward as it descends toward calcaneus - Clockwise left, counterclockwise right

Question 46

Gastrocnemius tendon fibers

Answer 46

- Lateral at their insertion

Question 47

Soleus tendon fibers

Answer 47

- Medial at the insertion

Question 48

Calcaneal tendon (Achilles) has no tendon sheath

Answer 48

- Has a paratenon - Contains numerous small vessels that supply the tendon - Branches from fibular and posterior tibial artery

Question 49

Watershed area of calcaneal tendon (Achilles)

Answer 49

- Located 2-6 cm above insertion

Question 50

Retrocalcaneal bursa

Answer 50

- Superficial: between tendon and skin | - Deep: between tendon and trigonum achilleum