Standing quadriceps stretch:

Quadriceps stretching is important for improving range of motion in the hips and knees.
In a standing position bend one knee and grasp your ankle with your hand.
You can hold onto a wall or other object for balance.
Pull your foot up and away from your buttocks keeping your knee facing toward the ground.

Do NOT try to touch your buttocks with the heel of your foot as the muscle needs to stretch over your knee and hip.
Hold for 30 seconds and repeat 3 times before performing on the other side.