O & I: Superficial Muscles of Posterior Leg

Question 1

Origin: Gastrocnemius

Answer 1

Lateral head: lateral aspect of lateral condyle of femur

Medial head: popliteal surface of femur; superior to medial condyle

Question 2

Insertion: Gastrocnemius

Answer 2

posterior surface of calcaneus via calcaneal tendon

Question 3

Innervation: Gastrocnemius

Answer 3

Tibial Nerve (S1, S2)

Question 4

Action: Gastrocnemius

Answer 4

plantarflexes ankle when knee is extended; raises heel during walking; flexes leg at knee joint

Question 5

Function: Gastrocnemius

Answer 5

Calcaneal tendon spirals 90 deg. During its descent, so that the gastroc. Fibers attach laterally and the soleal fibers attach medially. Arrangement is significant to the tendon’s elastic ability to absorb energy (shock) and recoil, releasing the energy as part of the propulsive force it exerts

Question 6

Origin: Soleus

Answer 6

posterior aspect of head and superior quarter of posterior surface of fibula; soleal line and middle third of medial border of tibia; and tendinous arch extending between the bony attachments

Question 7

Insertion: Soleus

Answer 7

posterior surface of calcaneus via calcaneal tendon

Question 8

Innervation: Soleus

Answer 8

Tibial Nerve (S1, S2)

Question 9

Action: Soleus

Answer 9

plantarflexes ankle independent of position of knee; steadies leg on foot

Question 10

Function: Soleus

Answer 10

Calcaneal tendon spirals 90 deg. During its descent, so that the gastroc. Fibers attach laterally and the soleal fibers attach medially. Arrangement is significant to the tendon’s elastic ability to absorb energy (shock) and recoil, releasing the energy as part of the propulsive force it exerts

Question 11

Origin: Plantaris

Answer 11

Inferior end of lateral supracondylar line of femur; oblique popliteal ligament

Question 12

Insertion: Plantaris

Answer 12

posterior surface of calcaneus via calcaneal tendon

Question 13

Innervation: Plantaris

Answer 13

Tibial Nerve (S1, S2)

Question 14

Action: Plantaris

Answer 14

weakly assists gastrocnemius in plantarflexing ankle