1. Muscles that act on the lower legs
1. Quadriceps femoris- anterior extensors
a. Rectus femoris- also extends thigh, runs parallel through the midline
1. Originates from inferior iliac spine
2. Inserts at upper border of patella

3. b. Vastus lateralis
1. Originates from greater trochanter and linea aspera
2. Inserts at tibial tuberosity through patellar ligament
c. Vastus medialis
1. Originates from linea aspera
d. Vastus intermedialis
1. Originates from anterior, lateral surface of femur

5. 2. Sartorius- flexes thigh and rotates laterally
a. Originates from anterior superior iliac spine
b. Inserts at medial surface of the tibia

8. 3. Hamstrings- posterior flexors and extend thigh
a. Biceps femoris
1. Long head from ischial tuberosity, short from linea aspera
2. Inserts at head of fibula and lateral condyle of tibia
b. Semitendinosus
1. Origin is ischial tuberosity
2. Inserts at proximal part of medial surface of tibia

10. c. Semimembranosus
1. Origin is ischial tuberosity
2. Inserts at medial condyle of tibia