What is a one-sentence summary of the following article?
Make sure your feet are together with your toes pointed forward. Raise your arms straight up into the air above your head.  The straight jump is a fairly basic jump that is safe to do at home. It will help you to strengthen your legs, improve your cardiovascular endurance, and learn to keep your balance. While you are unlikely to hurt yourself doing this jump, you could still potentially twist your ankle or fall. While you squat, simultaneously swing your arms back behind you. Make sure your arms are as far back as they can go while you reach the lowest part of your squat. Don't go so far down as to lose your balance, but spread your arms to the side if you need to. Push off of your feet and extend your legs. You will return to your original position with straight legs and upper body, but now you will be airborne. As you pop upward like a spring, swing your arms back up over your head for added momentum. Gymnasts coined this phrase to describe a method of landing on their feet that absorbs the shock and prevents injuries. To do this, land with your legs apart and knees slightly bent. Hold your arms out for balance. In a perfectly stuck landing, your feet should not move at all.

Summary:
Stand up straight. Begin your jump by bending your knees. Spring up into the air. Stick the landing.