The Leg

Question 1

Dermatomes of the leg

Answer 1

Medial side- L4.
Lateral side - L5
Back- S2 , S1

Question 2

State the boundaries and contents of the Anterior leg compartment.

( Extensor compartment)

Answer 2

Boundaries:
Anterior- deep fascia of the leg
medial- lateral surface of shaft of fibia
lateral- anterior intermuscular septum
Posterior- interosseous membrane

CONTENTS
-Muscles: tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius.
-Anterior tibial artery
-Deep peroneal nerve(anterior tibial nerve)

all muscles are dorsiflexors and arise from fibula except tibialis anterior

Question 3

State the boundaries and contents of the Lateral compartment

(peroneal)

Answer 3

Boundaries:
Anterior-anterior intermuscular septum
Posterior- posterior intermuscular septum
Medial- lateral surface of fibula
Lateral-deep fascia of leg

CONTENTS:
-Muscles- peroneus longus and peroneus brevis ( evertors and plantar flexors)
-Superficial peroneal nerve
-veins- small unnamed veins mostly drain into small saphenous vein.

contents are supplied by branches of peroneal artery which is a branch of posterior tibial artery

does not have its own artery

Question 4

State the boundaries and contents of the Posterior compartment

Answer 4

Boundaries
Anterior- posterior surfaces of tibia, fibula,interosseous membrane and posterior intermuscular septum.
Posterior- deep fascia of the leg

Divisions:
1. superficial- between superficial transverse spetum and deep fascia. (contains gatrocnemius, soleus and plantaris)
2. middle- between superficial and deep transverse septa.( conatins flexor digitorum longus, flexor hallucis longus, posterior tibial nerve and vessels)
3. deep- between deep transverse septum and posterior surfaces of interosseous membrane, tibia and fibula. (contains tibialis posterior)

Contents:
-Muscles- superficial( gastrocnemius, plantaris, soleus) and deep(popliteus,FDL, FHL, TP)
-Arteries- Posterior tibial artery,Peroneal artery
-Nerve- Tibial nerve

Question 5

Clinical relevance of the leg compartments

Answer 5

Posterior:
1. peripheral heart- soleous has rich venous plexus, contraction of soleous helps drain blood from superficial veins and pumps it to deep veins.
2. Triceps surae form calf muscle pump- facilitates venous return

Anterior:
1. Anterior tibial compartment syndrome- muscles of the compartment swell due to sudden overuse which may impede venous return leading to accumulation of fluid. Compression of anterior tibial artery occurs and causes ischemia and pain.( fresher’s syndrome)

triceps surae- 2 heads of gastrocnemius and soleus