In order to perform a Back Tuck in gymnastics, you should stand with your legs hip distance apart. Next, you should squat down. Don't squat too deep, because it will decrease your power. But, it should be a good deep squat. Swing your arms behind you at the same time. Next, jump up into the air, swinging your arms through and up. Extend your body as much as you can, from your fingers to your toes. When fully extended, your arms should be near your ears. When you have extended as far as you can tuck your knees into your chest and grab them with your hands. Remain in a tucked position, until you are able to spot the ground/floor.