The quadriceps stretch stretches your quadriceps muscles in front of your hip and thigh. Improving the flexibility of your quadriceps muscles makes it easier to move your hip and knee, which decreases stress on your lower back.
Get into a comfortable position lying on your mat on your stomach. Bend one knee and grasp your foot with your hand.
Use your hand to help you bend your knee as far as you can. You should feel a "gentle discomfort" with this stretch. It should not be painful. Hold the static stretch for 30 seconds. Then lower your leg back down to the starting position.