Hamstring Muscles of the knee

Question 1

State the hamstring muscles

Answer 1

Biceps femoris
Semitendinosus
Semimembranosus

Question 2

State the muscle attachments and action of biceps femoris

Answer 2

Origin: 2 heads
Long head- infermedial part of upper area ischial tuberosity
Short head- lateral lip linea aspera
Insertion: head of fibula
Action: flexion and ER of the knee
Nerve: sciatic L5-S2

Question 3

State the muscle attachment and action of semitendinosus

Answer 3

Origin: inferomedial part upper area ischial tuberosity.
Insertion: medial surface proximal tibia.

Action: flexion and IR of the knee

Nerve supply: sciatic nerve L5-S2

Question 4

State the muscle attachment and action of semimembranosus

Answer 4

Origin: superolateral impression ischial tuberosity

Insertion: groove and adjacent bone medial and posterior surface medial tibial condyle

Action: flexion and IR

Nerve supply: sciatic nerve L5-S2

Question 5

What is the function of the hamstrings?

Answer 5

All 3 extend the hip and flex the knee joint.
BF laterally rotates the hip and knee joints
ST and SM medially rotate the hip and knee joints