Leg Anatomy

Muscles of the Leg

	Muscle	Innervation	Origin	Insertion	Action	Nerve Root
	Anterior Compartment
1	Tibialis Anterior	Deep peroneal	Lateral tiba	Med. Cuneiform, 1st metatarsal	Dorsiflex, invert foot	L4
2	Extensor Hallucis longus (EHL)	Deep peroneal	mid fibula	great toe distal phalanx	dorsiflex, extend toe	L5
3	Extensor digitorum longus(EDL)	Deep peroneal	tibial condyle/fibula	toe middle & distal phalanges	dorsiflex, extend toes	L5
4	Peroneus tertius	Deep peroneal	fibula & EDL tendon	5th metatarsal	evert, planter flex, abduct foot	S1
	Lateral Compartment
1	Peroneus longus	superficial peroneal	proximal fibula	med cuneiform, 1st metatarsal	evert, plantar flex, abduct foot	S1
2	Peroneus brevis	superficial peroneal	distal fibula	tuberosity of 5th metatarsal	evert foot	S1
	Superficial Posterior Compartment
1	Gastrocnemius	tibial	post med and lat femoral condyles	calcaneus	plantar flex foot	S1
2	Soleus	tibial	fibula/tibia	calcaneus	plantar flex foot	S1
3	Plantaris	tibial	lat femoral condyle	calcaneus	plantar flex foot	S1
	Deep Posterior Compartment
1	Popliteus	tibial	lat femoral condyle, fibular head	proximal tibia	flex, IR knee	L5S1
2	Flexor hallucis longus(FHL)	tibial	fibula	great toe distal phalanx	plantar flex great toe	S1
3	Flexor digitorum longus(FDL)	tibial	tibial	2nd-5th distal phalanges	plantar flex toes, foot	S1S2
4	Tibialis Posterior	tibial	tibia, fibula, interosseous membrane	navicular, med cuneiform	invert/plantar flex foot	L4L5

Posterolateral Approach to Distal Tibia

• separates gastrocnemius and soleus from the peroneus brevis, exposing the FHL. 
• Deep dissection detaches FHL from fibula and tibialis posterior from the interosseous membrave. 
• Some fibers of FHL are reflected off posterior tibia to access bone.

Innervation

• Common Peroneal Neve:
• Deep Peroneal Nerve is in anterior compartment, suplies sensation to dorsal web space first and second toes, and is motor to toe dorsiflexors
• Superficial Peroneal nerve is in lateral compartment, sensory to rest of dorsal foot, motor to the foot evertors
• Tibial nerve sensory to sole of foot and motor to toe plantarflexors, travels in deep posterior compartment
• Sural nerve