Knee Extensors

Question 1

What is the origin,insertion and action for Rectus femoris

Answer 1

Origin - straight head - AIIS
Short head - rough area of ilium superior to acetabulum
Insertion - 2 heads join the quadriceps femoris tendon which inserts into base of patella
Action - 2 joint muscle, extends knee and flexes hip

Question 2

What is the origin,insertion and action for vastus inter Medius

Answer 2

Origin - femur upper 2/3rds anterior and lateral surfaces
Insertion - deep quadriceps tendon and lateral border of patella
Action - extends knee

Question 3

What is the origin,insertion and action of vastus medialis

Answer 3

Origin - femur medial of introchanteric line, pectineal line, medial lip of linea aspera and medial surpracondylar ridge
Insertion - quadriceps tendon and medial border of patella
Action - extends knee

Question 4

What is the origin,insertion and action of vastus lateralis

Answer 4

Origin - lateral part of intertrochanteric line, lateral greater trochanter, lateral gluteal tuberosity and lateral lip linea aspera
Insertion - quadriceps tendon and lateral patella
Action - extends knee