Rule #2. Bend the Knees.

In proper structural alignment, the knees should be slightly bent and the butt tucked under as if you were sitting on a stool with your feet on the ground. Correct alignment: the tip of the nose, the center of the navel - and the tip of the toes. The nee caps must be directly aligned with your nose, toes, and navel, and should extend no further than the tip of the middle toes. Also be sure that the knees are pointed directly forward and not twisted inward or outward. If your knees are unable to point in the direction of your toes, most likely your hips are tight. Relaxing the knees will increase blood flow through the legs and make it easier to relax the hips.