Practical Class 3: Posterior Thigh and Popliteal Fossa

Question 1

With which bone does the femur articulate distally?

Answer 1

Tibia

Question 2

What is the linea aspera?

Answer 2

A ridge that runs longitudinally along the dorsal surface of the femur and form an attachment site for several muscles.

Question 3

What is the name of the fascia that surrounds the muscles of the thigh?

Answer 3

Fascia lata

Question 4

How does the fascia lata divide the thigh muscles into compartments?

Answer 4

Forms three intermuscular septa that attach to the linea aspera of the femur and divide the muscles of the thigh into three compartments:

• Anterior extensor
• Posterior flexor
• Medial adductor

Question 5

What names are given to the hamstring muscles?

Answer 5

• Semimembranosus
• Semitendinosus
• Biceps femoris (long head)

These muscles share a common proximal attachment and nerve supply.

Question 6

What is the proximal attachment and innervation of the hamstrings?

Answer 6

Proximal attachment - ischial tuberosity (long head of biceps femoris only)

Innervation - Tibial division of sciatic nerve, part of tibia (L1,S1-2) (long head of biceps femoris only)

Question 7

What is the distal attachment of semimembranosus?

Answer 7

Posterior part of medial condyle of tibia; reflected attachment forms oblique popliteal ligament (to lateral femoral condyle).

Question 8

What is the distal attachment of semitendinosus?

Answer 8

Medial surface of superior part of tibia.

Question 9

What is the distal attachment of biceps femoris (long head)?

Answer 9

Lateral side of head of fibula; tendon is split at this site by fibular collateral ligament of knee.

Question 10

What are the attachments and innervation of the short head of biceps femoris?

Answer 10

Proximal - Linea aspera and lateral supracondylar line of femur

Distal - Lateral side of head of fibula

Innervation - Common fibular division of sciatic nerve (L5, S1-2)

Question 11

What are the functions of the hamstrings at the hips?

Answer 11

• Semitendinosus and semimembranosus extend the hip when the trunk is fixed.
• The long head of the biceps femoris extends the hip as when beginning to walk.

Question 12

What are the functions of the hamstrings at the knee?

Answer 12

• Semitendinosus and semimembranosus flex the knee and medially (inwardly) rotate the lower leg when the knee is bent.
• Both short and long heads of biceps femoris flex the knee and laterally (outwardly) rotates the lower leg when the knee is bent.

Question 13

Which muscle is also has a part that is considered part of the hamstrings? Which compartment does it belong to?

Answer 13

Adductor magnus (hamstring part) - part of the medial compartment.

Question 14

What is the nerve supply and proximal attachment for the adductor part of adductor magnus?

Answer 14

Nerve supply - posterior division of obturator nerve

Proximal attachment - Inferior pubic ramus, ischial ramus, and inferolateral area of ischial tuberosity

Question 15

What is the nerve supply and proximal attachment for the hamstring part of adductor magnus?

Answer 15

Nerve supply - Tibial division of sciatic nerve, part of tibia (L1,S1-2)

Proximal attachment - Inferior pubic ramus, ischial ramus, and inferolateral area of ischial tuberosity

Question 16

Into which nerves does the sciatic nerve divide?

Answer 16

Common fibular (lateral) and tibial (midline).

Question 17

What forms the upper border of the popliteal fossa?

Answer 17

Medially the distal ends of the semitendinosus and semimembranosus muscles and laterally the distal end of the biceps femoris muscle

Question 18

What forms the lower border of the popliteal fossa?

Answer 18

Lower - smaller lower part of the space are formed medially by the medial head of the gastrocnemius muscle and laterally by the plantaris muscle and the lateral head of the gastrocnemius muscle.

Question 19

What forms the floor of the popliteal fossa?

Answer 19

Floor - capsule of the knee joint and adjacent surfaces of the femur and tibia, and, more inferiorly, by the popliteus muscle.

Question 20

What forms the roof of the popliteal fossa?

Answer 20

Roof - deep fascia, which is continuous above with the fascia lata of the thigh and below with deep fascia of the leg.

Question 21

What divides the posterior compartment of the leg into superficial and deep compartments?

Answer 21

Transverse intermuscular septum.

Question 22

Which three muscles sit in the posterior compartment of the leg?

Answer 22

• Gastrocnemius
• Soleus
• Plataris