[header] How to jump from back on legs [title] Get on your back. [step] This step is seemingly the most simple, but you have to assure that there is nothing to hit your head on. Concussions are not exactly a fun things to have. 
Make sure that you have ample space to jump up and that there are no slippery rugs beneath you, as they could cause an unsafe slip and fall. [title] Lift your knees as close to your face as possible.