The Standard:
"On the command ‘get set,’ assume the front-leaning rest position by placing your hands where they are comfortable for you. Your feet may be together or up to 12 inches apart. When viewed from the side, your body should form a generally straight line from your shoulders to your ankles. On the command ‘go,’ begin the push-up by bending your elbows and lowering your entire body as a single unit until your upper arms are at least parallel to the ground. Then, return to the starting position by raising your entire body until your arms are fully extended. Your body must remain rigid in a generally straight line and move as a unit while performing each repetition. At the end of each repetition, the scorer will state the number of repetitions you have completed correctly. If you fail to keep your body generally straight, to lower your whole body until your upper arms are at least parallel to the ground, or to extend your arms completely, that repetition will not count, and the scorer will repeat the number of the last correctly performed repetition. An altered, front-leaning rest position is the only authorized rest position. That is, you may sag in the middle or flex your back. When flexing your back, you may bend your knees, but not to such an extent that you are supporting most of your body weight with your legs. If this occurs, your performance will be terminated. You must return to, and pause in, the correct starting position before continuing. If you rest on the ground or raise either hand or foot from the ground, your performance will be terminated. You may reposition your hands and/or feet during the event as long as they remain in contact with the ground at all times."
Alan