Leg Muscles

Question 1

Soleus

Answer 1

Origin: Soleal line of tibia, head/neck of fibula
Insertion: Calcaneal tuberosity via Achilles tendon
Action: Plantarflexion foot, Stabilizes leg on foot
Innervation: Tibial nerve S1, S2

Question 2

Gastrocnemius

Answer 2

Origin: medial and lateral epicondyle of the femur
Insertion: calcaneal tuberosity via Achilles tendon
Action: plantarflexion of foot when knee extended, flexion at knee
Innervation: tibial nerve S1, S2

Question 3

Plantaris

Answer 3

Origin: lateral epicondyle of femur
Insertion: calcaneal tuberosity via Achilles tendon
Action: weak plantarflexion
Innervation: tibial nerve S1, S2

Question 4

Popliteus

Answer 4

Origin: lateral femoral condyle
Insertion: proximal posterior tibial surface
Action: weakly flexes at the knee and unlocks it by rotating femur 5* on fixed tibia, internal rotation of tibia of unplanted limb
Innervation: tibial nerve L4, L5, S1

Question 5

Tibialis posterior

Answer 5

Origin: proximal posterior tibia, interosseous membrane, posterior fibula
Insertion: navicular, cuboid, sustentaculum tali of calcaneus, medial, intermediate, and lateral cuneiforms, base of metatarsals 2-4
Action: plantar flexion of foot, inversion foot
Innervation: tibial nerve L4, L5

Question 6

Flexor digitorum longus

Answer 6

Origin: middle posterior tibia
Insertion: base of distal phalanges 2-5
Action: plantarflexion of foot, inversion foot, flexion toes at MTP and IP joints 2-5
Innervation: tibial nerve S2, S3

Question 7

Flexor hallucis longus

Answer 7

Origin: inferior posterior fibula, interosseous membrane
Insertion: base of distal phalanx of great toe
Action: flexion great toe, plantarflexion foot
Innervation: tibial nerve S2, S3

Question 8

Tibialis anterior

Answer 8

Origin: proximal lateral tibia, interosseous membrane
Insertion: medial cuneiform, base of 1st metatarsal
Action: Dorsiflexion foot, inversion foot
Innervation: Deep fibular nerve L4, L5

Question 9

Extensor digitorum longus

Answer 9

Origin: medial surface of fibula, lateral tibial condyle, interosseous membrane
Insertion: base of middle & distal phalanges 2-5
Action: dorsiflexion foot, extension toes at MTP and IP joints 2-5
Innervation: Deep fibular nerve L4, L5

Question 10

Extensor hallucis longus

Answer 10

Origin: anterior surface fibula, interosseous membrane
Insertion: base of 1st distal phalanx
Action: extension at great toe, dorsiflexion at foot
Innervation: Deep fibular nerve L4, L5

Question 11

Fibularis (peroneus) tertius

Answer 11

Origin: distal anterior fibula w/ extensor digitorum longus
Insertion: dorsal border of 5th metatarsal
Action: dorsiflexion foot, eversion foot
Innervation: Deep fibular nerve L4, L5

Question 12

Fibularis longus (peroneus longus)

Answer 12

Origin: Proximal lateral fibula, head of fibula
Insertion: base of 1st metatarsal, medial cuneiform
Action: eversion foot, plantarflexion foot
Innervation: superficial fibular nerve L5, S1, S2

Question 13

Fibularis brevis

Answer 13

Origin: distal lateral fibula, interosseous membrane
Insertion: tuberosity of 5th metatarsal
Action: eversion foot, plantarflexion foot
Innervation: superficial fibular nerve L5, S1, S2