MOINA Muscles of the Posterior Fascial Compartment of the Leg

Question 1

gastrocnemius

Answer 1

origin: lateral condyle of femur (lateral head) and above medial condyle of femur (medial head)
insertion: via tendo calcaneus into posterior surface of calcaneum

nerve: tibial nerve

plantar flexes foot at ankle joint; flexes leg at knee joint

Question 2

plantaris

Answer 2

origin: lateral supracondylar ridge of femur
insertion: posterior surface of calcaneus

nerve: tibial nerve

plantar flexes foot at ankle joint; flexes leg at knee joint

Question 3

soleus

Answer 3

origin: shafts of tibia and fibula
insertion: via tendo calcaneus into posterior surface of calcaneum

nerve: tibial nerve

together with gastrocnemius and plantaris is a power plantar flexor of the foot; provides main propulsive force in walking and running

Question 4

popliteus

Answer 4

origin: lateral surface of lateral condyle of femur
insertion: posterior surface of shaft of tibia above soleal line

nerve: tibial nerve

flexes leg at knee joint; unlocks knee joint by lateral rotation of femur on tibia and slackens ligaments of joint

Question 5

flexor digitorum longus

Answer 5

origin: posterior surface of shaft of tibia
insertion: bases of distal phalanges of lateral four toes

nerve: tibial nerve

flexes distal phalanges of lateral four toes; plantar flexes foot at ankle joint; supports medial and lateral longitudinal arches of the foot

Question 6

flexor hallucis longus

Answer 6

origin: posterior surface of shaft of fibula
insertion: base of distal phalanx of big toe

nerve: tibial nerve

flexes distal phalanx of big toe; plantar flexes foot at ankle joint; supports medial longitudinal arch of the foot

Question 7

tibialis posterior

Answer 7

origin: posterior surface of shafts of tibia and fibula
insertion: tuberosity of navicular and other neighboring bones

nerve: tibial nerve

plantar flexes foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; supports medial longitudinal arch of the foot