Leg

Question 1

Extensor Digitorum Longus

Answer 1

Origin: anterior surface of shaft of fibula
Insertion: extensor expansion of lateral four toes
Nerve: deep peroneal nerve
Action: extends toes; extends foot at ankle joint

Question 1

Tibialis Anterior

Answer 1

Origin: lateral surface of shaft of tibia and interosseous membrane
Insertion: medial cuneiform and base first metatarsal bone
Nerve: deep peroneal nerve
Action: extends foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; holds up the medial longitudinal arch of the foot

Question 2

Peroneus Tertius

Answer 2

Origin: anterior surface of shaft of fibula
Insertion: base of fifth metatarsal bone
Nerve: deep peroneal nerve
Action: extends foot at ankle joint; everts foot at subtalar and transverse tarsal joints

Question 3

Extensor Hallucis Longus

Answer 3

Origin: anterior surface of shaft of fibula
Insertion: base of distal phalanx of great toe
Nerve: deep peroneal nerve
Action: extends big toe; extends foot at ankle joint; inverts foot at subtalar and transverse tarsal joints

Question 4

Extensor Digitorum Brevis

Answer 4

Origin: calcaneum
Insertion: by four tendons into proximal phalanx of big toe and long extensor tendons to second, third, and fourth toes
Nerve: deep peroneal nerve
Action: extends toe

Question 5

Peroneal Longus

Answer 5

Origin: lateral surface of shaft of fibula
Insertion: base of first metatarsal and medial cuneiform
Nerve: superficial peroneal nerve
Action: plantar flexes foot at ankle joint; everts foot at subtalar and transverse tarsal joints; supports lateral longitudinal and transverse arches of the foot

Question 6

Peroneus Brevis

Answer 6

Origin: lateral surface of shaft of fibula
Insertion: base of fifth metatarsal bone
Nerve: superficial peroneal nerve
Action: plantar flexes foot at ankle joint; extends subtalar and transverse tarsal joints; supports longitudinal arch of the foot

Question 7

Gastrocnemius

Answer 7

Origin: lateral head from lateral condyle of femur and medial head from above medial condyle
Insertion: via tendon calcaneus into posterior surface of calcaneum
Nerve: tibial nerve
Action: plantar flexes foot at ankle joint: flexes knee joint

Question 8

Plantaris

Answer 8

Origin: lateral supracondylar ridge of femur
Insertion: posterior surface of calcaneum
Nerve: tibial nerve
Action: plantar flexes foot at ankle joint: flexes knee joint

Question 9

Soleus

Answer 9

Origin: shafts of tibia and fibula
Insertion: via tendo calcaneus into posterior surface of calcaneum
Nerve: tibial nerve
Action: together with gastrocnemius and plantaris forms a powerful plantar flexor of the ankle joint: provides main propulsive force in walking and running

Question 10

Popliteus

Answer 10

Origin: lateral surface of lateral condyle of femur
Insertion: posterior surface of shaft of tibia above soleal line
Nerve: tibial nerve
Action: flexes leg at ankle joint; unlocks ankle joint by lateral rotation of tibia and femur; slackens ligaments of joint

Question 11

Flexor Digitorum Longus

Answer 11

Origin: posterior surface of shaft of tibia
Insertion: bases of distal phalanges of lateral four toes
Nerve: tibial nerve
Action: flexes distal phalanges of lateral four toes; plantar flexes foot at the ankle joint; supports medial and lateral longitudinal arches of the foot

Question 12

Flexor Hallucis Longus

Answer 12

Origin: posterior surface of shaft of fibula
Insertion: base of distal phalanx of big toe
Nerve: tibial nerve
Action: flexes distal phalanx of the big toe; plantar flexes foot at the ankle joint; supports medial longitudinal arch of the foot

Question 13

Tibialis Posterior

Answer 13

Origin: posterior surface of shafts of tibia and fibula and interosseous membrane
Insertion: tuberosity of navicular and other neighboring bones
Nerve: tibial nerve
Action: plantar flexes foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; supports medial longitudinal arch of the foot