What is the best way to stretch my rectus femoris?

Heel to buttocks: A slow static stretch is best and achieved by holding on to a stable object with one hand. The other hand grasps the ankle of the same side of the rectus to be stretched. By gently bending your knee and bringing the heel of your foot up towards the same side of your buttocks, hold that position for a count of 10, release to straighten the knee and repeat 3-5 times.

2 joint muscle: The rectus femoris starts at the top of the hip bone and ends below the knee. You use it to lift your leg (for example when taking a step up) and to straighten your knee. Since it crosses two joints, the hip needs to be extended and the knee bent to stretch it. The best method depends on your current fitness level and activities. It is best to have an athletic trainer/ physical therapist show you.