Posterior thigh, popliteal fossa and knee

Question 1

What is the insertion of biceps femoris long head?

Answer 1

head of fibula

Question 2

What is the innervation of biceps femoris long head?

Answer 2

Tibial n (L5-S2)

Question 3

What is the action of biceps femoris long head?

Answer 3

hip: extension, stabilizes the pelvis in the sagittal plane
knee: flexion and external rotation

Question 4

What is the origin of biceps femoris short head?

Answer 4

lateral lip of the linea aspera in the middle third of the femur

Question 5

What is the insertion of biceps femoris short head?

Answer 5

head of fibula

Question 6

What is the innervation of biceps femoris short head?

Answer 6

common fibular n (L5-S2)

Question 7

What is the action of biceps femoris short head?

Answer 7

flexion and external rotation of knee

Question 8

What is the origin of semitendinosus?

Answer 8

Ischial tuberosity and sacrotuberous ligament (common head with long head of biceps femoris)

Question 9

What is the insertion of semitendinosus

Answer 9

medial to the tibial tuberosity in the pes anserinus (along with the tendons of gracilis and sartorius)

Question 10

What is the innervation of semitendinosus?

Answer 10

Tibial n (L5-S2)

Question 11

What is the action of semitendinosus?

Answer 11

Hip joint: extends the hip, stabilizes the pelvis in the sagittal plane
Knee joint: flexion and internal rotation

Question 12

What is the origin of semimembranosus?

Answer 12

Ischial tuberosity

Question 13

What is the insertion of semimembranosus?

Answer 13

medial tibial condyle, oblique popliteal ligament, popliteus fascia

Question 14

What is the innervation for semimembranosus?

Answer 14

Tibial n (L5-S2)

Question 15

What is the action of semimembranosus?

Answer 15

Hip: extends the hip, stabilizes the pelvis in the sagittal plane
Knee: flexion and internal rotation

Question 16

What is the origin of gastocnemius?

Answer 16

medial and lateral epicondyles of femus

Question 17

What is the insertion of gastocnemius?

Answer 17

calcaneal tuberosity via the calcaneal tendon

Question 18

What is the innervation of gastrocmenius?

Answer 18

tibial n (S1,S2)

Question 19

What is the action of gastrocnemius?

Answer 19

talocrural joint: plantar flexion

knee joint: flexion

Question 20

What is the origin of popliteus?

Answer 20

lateral femoral condyle, posterior horn of the lateral meniscus

Question 21

What is the insertion of popliteus?

Answer 21

posterior tibial surface (above the origin at the soleus)

Question 22

What is the innervation of popliteus?

Answer 22

Tibial n (L4-S1)

Question 23

What is the action of popliteus?

Answer 23

flexion, internal rotation and stability of knee

Question 24

What is the origin of plantaris?

Answer 24

Femur (lateral epicondyle, proximal to lateral head of gastrocnemius)

Question 25

What is the insertion of plantaris?

Answer 25

calcaneal tuberosity

Question 26

What is the innervation of plantaris?

Answer 26

tibial n (S1-S2)

Question 27

What is the action of plantaris?

Answer 27

negligible

*may prevent the compression of posterior leg musculature during knee flexion

Question 28

What is the origin of biceps femoris long head?

Answer 28

ischial tuberosity, sacrotuberous ligament (common head with semitendinosus)