Leg Learning Objectives

Question 1

Explain the organization of the crural fascia its thickening, the extensor retinaculum.

Answer 1

Anterior: (both rarely torn)
Superior extensor retinaculum
Inferior extensor retinaculum

Lateral:
Superior fibular (peroneal) retinaculum
Inferior fibular retinaculum

Question 2

Describe the fascial compartments of the leg and list their contents, general actions, innervation, and blood supply.

Anterior compartment

Answer 2

Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Fibularis tertius

Ankle Dorsiflexion, inversion
Toe extension
(Ankle Eversion IF peroneus tertius could be isolated)

Innervated by deep fibular n.
Blood supply by anterior tibial a.

Question 3

Describe the fascial compartments of the leg and list their contents, general actions, innervation, and blood supply.

Lateral compartment

Answer 3

Fibularis longus
Fibularis brevis

Eversion, plantar flexion
(tendons posterior to fibula)

Innervated by superficial fibular n.
Blood supply by fibular a.

Question 4

Describe the fascial compartments of the leg and list their contents, general actions, innervation, and blood supply.

Posterior compartment, superficial

Answer 4

Triceps surae:
Gastrocnemius
Soleus
Plantaris

Ankle Plantar flexion
Knee flexion (weak, gastrocnemius & plantaris)

Innervated by the tibial n.
Blood supply by posterior tibial a.

Question 5

Describe the fascial compartments of the leg and list their contents, general actions, innervation, and blood supply.

Posterior compartment, deep

Answer 5

Popliteus
Flexor digitorum longus (FDL)
Flexor hallucis longus (FHL)
Tibialis posterior (TP)

Ankle plantar flexion, inversion
Toe flexion (FDL, FHL)
Knee Flexion (popliteus)

Innervated by tibial n.
Blood supply by posterior tibial a.

Question 6

Identify the segmental innervation of the skin of the leg using a dermatome map.

Answer 6

1st toe = L4
5th toe = S1

See dermatome map.

Question 7

Describe the path taken by and the location of muscular branch origin of the common fibular nerves in the leg.

Answer 7

Deep to proximal fibularis longus
Curves lateral to neck of fibula
Splits deep to fibularis longus
Becomes superficial and deep fibular nn.

Superficial fibular n.

• Begins at bifurcation of common fibular n.
• Supplies fibularis longus and brevis mm.
• Emerges as cutaneous branch after passing through crural fascia

Deep fibular n.

• Approaches the interosseus membrane
• Between tibialis anterior & extensor hallucis longus
• Descends with anterior tibial a.

Question 8

Describe the path taken by and the location of muscular branch origin of the tibial nerve in the leg.

Answer 8

Joins with popliteal a. v.

Continues on with posterior tibial a.

Gives off sural n.

Splits into lateral and medial plantar nn. in foot