Posterior Thigh Muscles

Question 1

What are the 3 hamstring (true) muscles

Answer 1

• Semitendonosus
• Semimembranosus
• Long head of biceps femorus

Question 2

What are the 3 criteria to be a true hamstring?

Answer 2

1. Proximal attachment to the ischeal tuberosity
2. Span and act on 2 joints (hip and knee)
   - extend hip
   - flex the leg at the knee
3. Innervated by tibial division of Sciatic nerve

Question 3

Does the short head of the biceps femorus meet the criteria to be a hamstring?

Answer 3

NOPERS

Question 4

Does the semitendinosus insert on the anterior/posterior surface of the tibia?

Answer 4

Anterior surface

-on the Pes Anserinus (on the anterior/medial surface of the tibia)

Question 5

Does the semimembranosus insert on the anterior/posterior surface of the tibia?

Answer 5

Posterior surface

-On the medial condyle of the tibia

Question 6

Where does the long head of the biceps femoris attach?

Answer 6

The lateral side of the head of the fibula

Question 7

What are the 2 hamstrings that attach medially?

Answer 7

• Semitendinosus

- Semimembranosus

Question 8

Besides extending the thigh, what is the action of the medially attaching muscles

Answer 8

Rotate the leg medially in flexion

Question 9

What is the hamstring muscle that attaches laterally?

Answer 9

Long head of the biceps femorus

Question 10

Since the BFemorus attaches laterally, what is its special action?

Answer 10

Rotates the leg laterally in flexion

Question 11

What is the attachment for the biceps femorus short head?

Answer 11

Same as the long head

-At the lateral side of the head of the fibula

Question 12

What is the innervation of the biceps femorus short head?

Answer 12

-The Common fibular branch of the Sciatic nerve

Question 13

Does the sciatic nerve leave the GSF superiorly/inferiorly to the piriformis?

Answer 13

Inferior to the piriformis

Question 14

What are the 2 separate nerves in the sciatic sheath?

Answer 14

• Tibial branch

- Common fibular branch

Question 15

Does the sciatic nerve innervate anything in the gluteal region?

Answer 15

NOPERS

Question 16

The sciatic nerve innervates what hamstring muscles

Answer 16

ALL

• Tibial = true hamstrings
• Common fibular= short head of biceps femorus

Question 17

What is the one exception to the sciatic nerve innervating everything below the knee?

Answer 17

-The saphenous nerve which innervates a small area of skin on the medial side of the leg and foot

Question 18

What does the saphenous nerve branch off of?

Answer 18

Femoral nerve