OINA: Legs (Posterior/Lateral)

Question 1

Peroneus Longus

Answer 1

O: Lateral Surface of shaft of fibula

I: Base of 1st metatarsal and medial cuneiform

N: Superficial peroneal nerve L5,S1,S2

A: Plantar flexes foot at ankle jt., everts foot at subtalar and transverse tarsal jt, supports lateral longitudinal and transverse arches of foot

Question 2

Peroneus Brevis

Answer 2

O: Lateral Surface of shaft of fibula

I: Base of 5th metatarsal bone

N: Superficial peroneal nerve L5,S1,S2

A: Plantar flexes foot at ankle jt, everts foot at subtalar and transverse tarsal jt, supports lateral longitudinal arch

Question 3

Contents of posterior fascial compartment of the leg

Answer 3

Superficial group of muscle: Gastrocnemius, Plantaris, and Soleus

Deep group of muscles: Popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior

Blood Supply: Posterior tibial artery

Nerve Supply: Tibial nerve

Question 4

Gastrocnemius

Answer 4

O: Lateral head from lateral condyle of femur and medial head from above medial condyle

I: Via tendo calcaneus into posterior surface of calcaneum

N: Tibial nerve L5, S1

A: Plantar flexes foot at ankle joint, flexes jt.

Question 5

Plantaris

Answer 5

O: Lateral Supracondylar ridge of femur

I: Posterior surface of calcaneum

N: Tibial nerve S1,S2

A: Plantar flexes foot at ankle jt. and flexes knee jt.

Question 6

Soleus

Answer 6

O: Shaft of tibia and fibula

I: Via tendo calcaneus into posterior surface of calcaneum

N: Tibial nerve S1,S2

A: Together with gastrocnemius and plantaris is a powerful plantar flexor of ankle jt, provide main propulsive force in walking and running

Question 7

Popliteus

Answer 7

O: Lateral surface of lateral condyle of femur

I: Posterior surface of shaft of tibia above soleal line

N: Tibial nerve L4,L5,S1

A: Flexes leg at knee jt, unlocks knee joint by ER of femur on tibia and slackens ligaments of joint

Question 8

Flexor digitorum longus

Answer 8

O: Posterior surface of shaft of tibia

I: Bases of distal phalanges of lateral four toes

N: Tibial nerve S2,S3

A: Flexes distal phalanx of lateral four toes, plantar flexes foot at ankle jt, supports medial and lateral longitudinal arches of foot

Question 9

Flexor Hallucis Longus

Answer 9

O: Posterior surface of shaft of fibula

I: Base of distal phalanx of big toe

N: Tibial nerve S2,S3

A: Flexes distal phalanx of big toe, plantar flexes foot at ankle jt, supports medial longitudinal arch of foot

Question 10

Tibialis Posterior

Answer 10

O: Posterior surface of shaft of tibia, fibula and interosseous membrane

I: Tuberosity of navicular bone and other neighboring bones

N: Tibial nerve L4,L5

A: Plantar flexes foot at ankle jt, inverts foot at subtalar and transverse tarsal jts, supports medial longitudinal arch of foot