Posterior thigh: flexors of the leg

Question 1

semitendinosus

Answer 1

• origin: ischial tuberosity (common tendon with biceps femoris m.)
• insertion: medial surface of tibia (via pes anserinus)
• action: extends the thigh, flexes the leg

Question 2

semimembranosus

Answer 2

• origin: ischial tuberosity
• insertion: medial condyle of the tibia
• action: extends thigh, flexes the leg
• insertion tendon gives rise to lateral expansion inti knee joint capsule forming much of oblique popliteal ligament

Question 3

biceps femoris: long and short head

Answer 3

• origin: long head: ischial tuberosity; short head: lateral lip of the linea aspera,lateral supracondylar line
• insertion: common tendon to head of fibula and lateral condyle of the tibia
• tendon split by fibular collateral ligament
• action: flexes leg at knee, long head extends thigh at hip