Any part of body, except hands and toes, resting on ground. When maximum number is reached. When failing to complete a proper pushup. Hands locked behind head during exercise. Knees bent, feet no further than shoulder width apart.
Touch elbow to knee.
Shoulder blades must ground when down. Bouncing rear end off ground to gain momentum. Shoulder blades not touching ground when down. After 2-minute time limit or maximum number is reached. Time for 2 minutes.