I'll tell you how to practice your lower back. Find a tree, hold it in your hand, keep your back to the tree at arm's length, and keep your legs shoulder-width apart. Head back, hands back, hold the tree. Slowly move the hand holding the tree down alternately until you feel that you can't go down any more, then slowly straighten up and practice many times a day. Keep practicing for a few days, touch the ground with your hands, and then slowly support the ground with your hands, and you can practice. . . 13-year-old girl's waist is already very soft, and it won't take a few days. Just be careful not to use brute force, not to bend too hard at a time, step by step, pay attention to safety, and don't wear shoes with too slippery soles! ! ! ! ! !

Also pay attention to the tree you are looking for, not the tree where dogs pee. You can also find poles instead of trees in the fitness equipment in the community now. . . However, it should be noted that the upright floors of general community fitness equipment are all concrete, which is not as safe as the grass under the tree, even if it smells like dog urine. . . It is said that the best way to meet your requirements is to have a rod-shaped column at home, because you can put a mat on the floor for protection at any time, but there seems to be no such column at home, and the ground at home is generally slippery, but it is easy to slip when you lean back. Even if you have a cushion, you may even slip with the cushion and cause physical injury. If you hit any furniture and household items, it may cause more damage, so it is best not to practice bending at home, at most. . .