MUSCLE OF THE LEG  

There are Three Compartment Muscles of the leg

1) Anterior leg muscle

2) posterior leg muscle (calf muscle)

3) lateral leg muscle 

1) ANTERIOR LEG MUSCLE

Anterior Leg Muscles

There are 5 muscle in anterior compartment of leg muscles.

1) Tibialis anterior

2) Extensor hallucis longus

3) Extensor digitorum longus

4) Extensor digitorum brevis

5) Peroneus tertius

1) TIBIALIS ANTERIOR

ORIGIN: Lateral tibial condyle and upper 2/3 of

lateral surface of tibia, interosseous membrane.

INSERTION: Medial and inferior surface of medial cuneiform, base of first metatarsal.

NERVE SUPPLY: Deep peroneal nerve (L4,L5).

ACTION: Dorsiflexes and inverts ankle.

2) EXTENSOR HALLUCIS LONGUS

ORIGIN: Fibula (shaft, middle ½ of medial aspect), interosseous membrane.

INSERTION: Hallux (distal phalanx, dorsal aspect of bases), expansion to proximal phalanx.

NERVE: Deep peroneal nerve (L5).

ACTION: Extends great toe, ankle dorsiflexor.

3) EXTENSOR DIGITORUM LONGUS

ORIGIN: Upper three quarter of medial surface of fibula, interosseous membrane, lateral tibial condyle.

INSERTION: Middle and distal phalanges of four lateral toes.

NERVE SUPPLY: Deep peroneal nerve (L5, S1).

4) EXTENSOR DIGITORUM BREVIS

ORIGIN: Calcaneus (anterior superolateral surface), lateral talocalcaneal ligament. Extensor retina-culum (inferior).

INSERTION: Base of proximal phalanx of great toe, lateral side of dorsal hood of adjacent three toes.

NERVE SUPPLY: Deep peroneal nerve (L5, S1).

ACTION: Extends great toe and adjacent three toes.

5) PERONEUS TERTIUS

ORIGIN: Distal third of medial surface of fibula, interosseous membrane, intermuscular septum.

INSERTION: Medial aspect of base of fifth metatarsal.

NERVE SUPPLY: Deep peroneal nerve (L5, S1).

ACTION: Everts and dorsiflexes ankle.

2) POSTERIOR LEG MUSCLES 

A) Superficial muscle of posterior leg

(CALF MUSCLE)

(mnemonic :- GPS)

Superficial Muscle of Posterior Leg Muscle

There are three muscle in superficially to posterior compartment of leg muscle 

1) G - Gastronimius 

2) P - Plantaris

3) S - Soleus

1) GASTROCNEMIUS

ORIGIN: 

Medial head—femur (posterior part of medial condyle).

Lateral head—femur (lateral surface of lateral

condyle).

INSERTION: Posterior surface of calcaneus.

NERVE SUPPLY: Tibial nerve (S1, S2).

ACTION: Plantar flexes ankle, flexes knee.

2) PLANTARIS

ORIGIN: Lateral supra condylar ridge, oblique popliteal ligament.

INSERTION: Tendocalcaneus.

NERVE SUPPLY: Tibial nerve (S1, S2).

ACTION: Plantar flexes ankle, flexes knee.

3) SOLEUS

ORIGIN: Soleal line and middle third of medial border of tibia, posterior surface of head and upper quarter of fibula, fibrous arch between tibia and fibula.

INSERTION: Posterior surface of calcaneus.

NERVE SUPPLY: Tibial nerve (S1, S2).

 ACTION: Plantar flexes ankle.

B) Deep muscle of posterior leg

Deep Muscle of Posterior Leg

1) Tibialis posterior

2) Flexors hallucis longus -----

3) Flexors digitorum longus -----

4) Popliteus

1) TIBIALIS POSTERIOR

ORIGIN: Tibia (lateral aspect of posterior surface, below soleal line, interosseous membrane, upper half of posterior surface of fibula, deep transverse fascia).

INSERTION: Tuberosity of navicular, medial cunei- form, sustentaculum tali, intermediate cuneiform, base of second to fourth metatarsals.

NERVE SUPPLY: Tibial nerve (L4,5).

ACTION: Plantar flexes and inverts ankle.

2) FLEXOR HALLUCIS LONGUS  

ORIGIN : Lower 2/3 of posterior fibula between median crest and posterior border

INSERTION: Base of distal phalanx of big toe 

NERVE SUPPLY: Tibial nerve ( S2, S3 )

ACTION: Flexion of distal phalnx of big toe and    Plantar flexes of  ankle 

3) FLEXOR HALLUCIS BREVIS 

 

ORIGIN : Planter aspect of cuniformis bone.

INSERTION: 

Medial head : medial side of base of proximal phalanx 

lateral head : lateral side of  base of proximal phalanx 

NERVE SUPPLY: Medial planter nerve ( S2, S3 )

ACTION: flexion of metacarpophalgeal joint of big toe 

4) POPLITEUS

ORIGIN: Outer surface of lateral femoral condyle.

INSERTION: Posterior surface of tibia above soleal line.

NERVE SUPPLY: Tibial nerve (L4–S1).

ACTION: Medially rotates tibia, flexes knee.

3) LETRAL LEG MUSCLE 

Lateral Leg Muscle

There are two muscle in lateral leg 

A) Peroneus longus

B) Peroneus brevis

A) PERONEUS LONGUS

ORIGIN: Lateral tibial condyle, upper 2/3 of lateral surface of fibula, intermuscular septa.

  

INSERTION: Lateral side of base of first metatarsal, medial cuneiform.

NERVE SUPPLY: Superficial peroneal nerve (L5, S1).

ACTION: Everts and plantar flexes ankle.

B) PERONEUS BREVIS

ORIGIN: Lower 2/3 of lateral surface at fibula, intermuscular septa.

INSERTION: Lateral side of base of fifth metatarsal.

NERVE SUPPLY: Superficial peroneal nerve (L5, S1).

ACTION: Everts and plantar flexes ankle.