Sports Med - Muscles of the Lower Leg

Gastrocnemius - Origin

Condyles of the femur, posterior surface

Gastrocnemius - Insertion

Calcaneus via calcaneal (Achilles) tendon

Gastrocnemius - Action

• Flex the knee

• Plantarflex the ankle

Soleus - Origin

Soleal line (on the tibia), posterior surface of the tibia, and posterior aspect of the head of the fibula

Soleus - Insertion

Calcaneus via calcaneal (Achilles) tendon

Soleus - Action

Plantarflex the ankle

Fibularis Longus - Origin

Head of the fibula and proximal two-thirds of lateral fibula

Fibularis Longus - Insertion

Base of the first metatarsal and medial cuneiform

Fibularis Longus - Action

• Evert the foot (eversion)

• Assist to plantarflex the ankle

Fibularis Brevis - Origin

Distal two-thirds of lateral fibula

Fibularis Brevis - Insertion

Tuberosity of the fifth metatarsal

Fibularis Brevis - Action

• Evert the foot (eversion)

• Assist to plantarflex the ankle

Tibialis Anterior - Origin

Lateral condyle of tibia, proximal and lateral surface of tibia, and interosseous membrane

Tibialis Anterior - Insertion

Medial cuneiform and base of the first metatarsal

Tibialis Anterior - Action

• Invert the foot (inversion)

• Dorsiflex the ankle

Extensor Digitorum Longus - Origin

Lateral condyle of tibia, proximal and anterior shaft of fibula, and interosseous membrane

Extensor Digitorum Longus - Insertion

Middle and distal phalanges of second through fifth toes

Extensor Digitorum Longus - Action

• Extend the second through fifth toes (extension)

• Dorsiflex the ankle

• Evert the foot (eversion)

Extensor Hallucis Longus - Origin

Middle anterior surface of the fibula and interosseous membrane

Extensor Hallucis Longus - Insertion

Distal phalanx of the first toe

Extensor Hallucis Longus - Action

• Extend the first toe (extension)

• Dorsiflex the ankle

• Invert the foot (inversion)

Tibialis Posterior - Origin

Proximal and posterior shafts of the tibia and fibula, and interosseous membrane

Tibialis Posterior - Insertion

All five tarsal bones (calcaneus, talus, cuboid, navicular, and the three cuneiforms) and bases of the second through fourth metatarsals

Tibialis Posterior - Action

• Invert the foot (inversion)

• Plantarflex the ankle

Flexor Digitorum Longus - Origin

Middle and posterior surface of the tibia

Flexor Digitorum Longus - Insertion

Distal second through fifth phalanges

Flexor Digitorum Longus - Action

• Flex the second through fifth toes

• Weak plantarflex of the ankle

• Invert the foot (inversion)

Flexor Hallucis Longus - Origin

Middle half of posterior fibula

Flexor Hallucis Longus - Insertion

Distal phalanx of the first toe

Flexor Hallucis Longus - Action

• Flex the big toe

• Weak plantarflex of the ankle

• Invert the foot (inversion)

Origin (definition)

The attachment site of a muscle that doesn’t move during muscle contraction, usually proximal

Insertion (definition)

The attachment site of a muscle that does move during muscle contraction, usually distal

What are the 4 muscle compartments of the lower leg?

Lateral, anterior, superficial posterior, and deep posterior

Lateral Compartment Structures

• Fibularis (peroneal) longus

• Fibularis (peroneus) brevis

• Superior peroneal retinaculum

• Inferior peroneal retinaculum

• Peroneus quartus

• Superficial peroneal nerve

• Peroneal artery

Anterior Compartment Structures

Everything extends

• Tibialis anterior

• Extensor hallucis longus

• Extensor digitorum longus

• Peroneus (fibularis) tertius

  • May be absent, not everyone has it

• Anterior tibial artery

  • Dorsal pedal artery

• Deep peroneal nerve

Superficial Posterior Compartment Structures

• Triceps surae muscle group (insertion point for all of these muscles is the achilles tendon)

  • Gastrocnemius

  • Plantaris

  • Soleus

    • Cannot be palpated

Deep Posterior Compartment Structures

• Tibialis posterior

• Flexor digitorum longus

• Flexor hallucis (big toe) longus

• Tibial nerve

• Posterior tibial artery

Anterior Compartment Structures - Main action

Dorsiflexion

Lateral Compartment Structures - Main action

Eversion

Superficial Posterior and Deep Posterior Compartment Structures - Main action

Plantarflexion

“Tom Hates Dirty Frogs”

Anterior Compartment Structures

Tom - Tibialis anterior

Hates - Extensor hallucis longus

Dirty - Extensor digitorum longus

Frogs - Fibularis tertius

“Long Beach”

Lateral Compartment Structures

Long - Longus —> Fibularis longus

Beach - Brevis —> Fibularis brevis

“GPS”

Superficial Posterior Compartment Structures

G - Gastrocnemius

P - Plantaris

S - Soleus

“Tom Dick An Harry”

Deep Posterior Compartment Structures

Tom - Tibialis posterior

Dick - Flexor digitorum longus

An - Artery and Nerve —> Posterior tibial artery

Harry - Flexor hallucis longus

Peroneal Longus - Origin

Head of the fibula and proximal two-thirds of lateral side of the fibula

Peroneal Longus - Insertion

Medial cuneiform and the base of the first metatarsal

Peroneal Longus - Action

• Evert the foot

• Assist to plantarflex the ankle

Peroneal Brevis - Origin

Distal two-thirds of the lateral side of the fibula

Peroneal Brevis - Insertion

Tuberosity of the fifth metatarsal

Peroneal Brevis - Action

• Evert the foot

• Assist to plantarflex the ankle