Muscles of the Lower Leg
Attachment sites (origin and insertion), actions, and innervation for the main muscles of the lower leg:
Extensor Digitorum Longus
Origin:
Lateral condyle of the tibia
Anterior shaft of fibula
Interosseous membrane
Insertion:
Middle & distal phalanges of 2nd-5th toes
Actions:
EXTEND toes 2 through 5 at the metatarsophalangeal and interphalangeal joints
DORSIFLEX the ankle at the talocrural joint
EVERT the foot at the subtalar joint
Innervation:
Deep fibular nerve
Fibularis Brevis
Origin:
Distal 2/3 of the lateral fibula
Insertion:
Tuberosity of the 5th metatarsal
Actions:
EVERT the foot at the subtalar joint
Assist to PLANTARFLEX the ankle at the talocrural joint
Innervation: Superficial fibular nerve
Fibularis Longus
Origin:
Head of the fibula
Proximal 2/3 of the lateral fibula
Insertion:
Base of the 1st metatarsal
Medial cuneiform
Actions:
EVERT the foot at the subtalar joint
Assist to PLANTARFLEX the ankle at the talocrural joint
Innervation:
Superficial fibular nerve
Flexor Digitorum Longus
Origin:
Middle, posterior surface of the tibia
Insertion:
Distal phalanges of 2nd - 5th toes
Actions:
FLEX toes 2 through 5
INVERT the foot at the subtalar joint
Weak PLANTAR FLEXION of the ankle at the talocrural joint
Innervation:
Tibial nerve
Flexor Hallucis Longus
Origin:
Middle half of posterior fibula
Insertion:
Distal phalanx of 1st toe
Actions:
FLEX 1st toes at the metatarsophalangeal and interphalangeal joints
INVERT the foot at the subtalar joint
Weak PLANTAR FLEXION of the ankle at the talocrural joint
Innervation:
TIbial Nerve
Gastrocnemius
Origin:
Posterior surfaces of the condyles of the femur
Insertion:
Calcaneus via calcaneal tendon
Actions:
FLEX the knee at the tibiofemoral joint
PLANTARFLEX the ankle at the talocrural joint
Innervation:
Tibial Nerve
Plantaris
Origin:
Lateral supracondylar line of the femur
Insertion:
Calcaneus via calcaneal tendon
Actions:
Weak FLEXION of the knee at the tibiofemoral joint
Weak PLANTAR FLEXION of the ankle at the talocrural joint
Innervation:
Tibial Nerve
Popliteus
Origin:
Lateral condyle of the femur
Insertion:
Proximal, posterior surface of the tibia
Actions:
MEDIALLY ROTATE the flexed tibiofemoral joint
FLEX the knee at the tibiofemoral joint
Innervation:
Tibial Nerve
Soleus
Origin:
Soleal line
Proximal, posterior surface of the tibia
Posterior aspect of the head of the fibula
Insertion:
Calcaneus via calcaneal tendon
Actions:
PLANTARFLEX the ankle at the talocrural joint
Innervation:
Tibial Nerve
Tibialis Anterior
Origin:
Lateral condyle of the tibia
Proximal, lateral surface of the tibia
Interosseous membrane
Insertion:
Base of the 1st metatarsal
Medial cuneiform
Actions:
DORSIFLEX the ankle at the talocrural joint
INVERT the foot at the subtalar joint
Innervation:
Deep FIbular Nerve
Tibialis Posterior
Origin:
Proximal, posterior shafts of the tibia and fibula
Interosseous membrane
Insertion:
All 5 tarsal bones
Bases of 2nd-4th metatarsals
Actions:
PLANTARFLEX the ankle at the talocrural joint
INVERT the foot at the subtalar joint
Innervation:
Tibial Nerve
Quiz Yourself
Put your knowledge to the test!
Flashcards
Joint Actions Quiz
What muscles plantarflex the ankle at the talocrural joint?
Gastrocnemius, Soleus, Tibialis Posterior, Fibularis Brevis (assists), Fibularis Longus (assists), Flexor Digitorum Longus (Weak), Flexor Hallucis Longus (weak), Plantaris (weak)