Function
The Rectus Femoris has 2 primary functions:
Extending the leg at the knee.This means that the rectus femoris muscle straightens the leg at the knee joint such that there is an increase in the angle between the lower leg and the upper leg.
Extending the leg at the knee.This means that the rectus femoris muscle straightens the leg at the knee joint such that there is an increase in the angle between the lower leg and the upper leg.
Performing some minor extension of the leg at the hip.