Muscles of the Leg

Question 1

Extensor Digitorum Longus

Answer 1

Origin Lateral condyle of tibia, anterior surface of fibula, lateral portion of
interosseous membrane
Insertion Dorsum of lateral 4 toes via extensor expansions (central slip inserts on
base of middle phalanx, lateral slip on base of distal phalanx)
Action Extends the metatarsophalan-geal (MTP), proximal interphalangeal
(PIP), and distal interphalangeal (DIP) joints of the lateral 4 toes
Innervation Deep fibular (peroneal) nerve
Artery Anterior tibial a.

Question 2

Extensor Hallucis Longus

Answer 2

Origin Middle½ of anterior surface of fibula and interosseous membrane
Insertion Base of distal phalanx of big toe
Action Extends MTP, PIP & DIP joints of big toe and dorsiflexes
Innervation Deep fibular (peroneal) nerve
Artery Anterior tibial a.

Question 3

Fibularis Tertius

Answer 3

Origin Distal part of anterior surface of fibula
Insertion Dorsum of the shaft of the 5th metatarsal
Action Everts the foot
Innervation Deep fibular (peroneal) nerve
Artery Anterior tibial a.

Question 4

Tibialis Anterior

Answer 4

Origin Lateral tibial condyle and upper lateral surface of tibia
Jnsertion Medial surface of the medial cuneiform and 1st metatarsal
Action Dorsiflexes and inverts the foot
Innervation Deep fibular (peroneal) nerve
Artery Anterior tibial a.

Question 5

Fibularis (Peroneus) Brevis

Answer 5

Origin Lower ½ of lateral surface of fibula
Insertion Tuberosity of the base of the 5th metatarsal
Action Extends (plantar flexes) and everts the foot
Innervation Superficial fibular (peroneal) nerve
Artery Fibular (peroneal) a.

Question 6

Fibularis (Peroneus) Longus

Answer 6

Origin Upper½ of lateral surface of fibula
Insertion First crossing the plantar surface of the foot deep to the intrinsic
muscles, it inserts on the medial cuneiform and the base of 1st
metatarsal
Action Extends (plantar flexes) and everts the foot
Innervation Superficial fibular (peroneal) nerve
Artery Fibular (peroneal) a.

Question 7

Flexor Digitorum Longus

Answer 7

Origin Middle ½ of posterior surface of tibia
Insertion Dorsum of the shaft of the 5th metatarsal(per the book) its actually DIstal phalanges 2-5
Action Flexes the MTP, PIP & DIP joints of digits 2-5; plantar flexes the foot
Innervation Tibial nerve
Artery Tibial a.

Question 8

Flexor Hallucis Longus

Answer 8

Origin Lower½ of posterior surface of fibula
Insertion Base of the distal phalanx of the big toe
Action Flexes the MTP & PIP joints of the big toe; plantar flexes the foot
Innervation Tibial nerve
Artery Fibular (peroneal) a., tibial a.

Question 9

Gastrocnemius

Answer 9

Origin Femur; medial head: above the medial femoral condyle
Lateral head: above the lateral femoral condyle
Insertion Dorsum of the calcaneus via the calcaneal (Achilles’) tendon
Action Flexes leg; plantar flexes foot
Innervation Tibial nerve
Artery Sural aa. (from popliteal a.), posterior tibial a.

Question 10

Plantaris

Answer 10

Origin Above the lateral femoral condyle (above the lateral head of
gastrocnemius)
Innsertion Dorsum of the calcaneus medial to the calcaneal tendon
Action Flexes leg; plantar flexes foot
Innnervation Tibial nerve
Artery Popliteal a.

Question 11

Popliteus

Answer 11

Origin Lateral condyle of the femur
Insertion Posterior surface of the tibia above soleal line
Action Flexes and rotates leg medially (with the foot planted, it rotates the thigh
laterally)
Innervation Tibial nerve
Artery Popliteal a.

Question 12

Soleus

Answer 12

Origin Posterior surface of head and upper shaft of fibula, soleal line of tibia
Insertion Dorsum of the calcaneus via the calcaneal (Achilles’) tendon
Action Plantar flexes the foot
Innervation Tibial nerve
Artery Posterior tibial a.

Question 13

Tibialis Posterior

Answer 13

Origin - lnterosseous membrane, posteromedial surface of fibula, posterolateral
surface of tibia
Insertion - Tuberosity of the navicular and medial cuneiform, metatarsals 2-4
Action - Plantar flexes & inverts the foot
Innervation - Tibial nerve
Artery - Fibular (peroneal) a., tibial a.