The human skeleton is like a deck of dominoes, and the intervertebral disc is the most important first card. Once this card falls, other bones and joints will be affected one after another, with a series of problems such as soreness, headache, hand numbness, chest tightness, flatulence, stiff neck, fatness, and even early aging. In everyday life, carrying a bag by hand will easily cause injury to the lumbar spine, so pay attention to the following points when carrying a backpack: 1. Handbags hurt the most waist Double backpacks can evenly distribute the pressure, one-shoulder back and handbag will cause excessive pressure on one side, the body is easy to lose balance. Especially when the single handbag, the force vertical down, hands and shoulders will not be affected, but the need for the other side of the waist force, it is easy to strain. Therefore, the handbag should be as light as possible, the weight should not exceed the weight of 10. In addition, the elbow joint nerves and fine, easy to be injured, when carrying a bag is best to hang the bag from the elbow joint a finger away, where the muscles are stronger, can support the weight of the backpack. 2, the more snug the backpack is the better When carrying a backpack, you should narrow your belly and relax your shoulders, the closer the strap is to your body, the shorter it is, the easier it is to carry it. If the backpack is too heavy, it is recommended to shorten the straps and keep the pack as close to the torso as possible, maintaining the height between the thoracic and lumbar vertebrae. Because if the backpack position is too high, it will compress the thoracic vertebrae; and hanging below the lumbar vertebrae will increase the burden on the backbone. 3, heavy things put in the middle will be heavy things in the middle of the backpack, walking when not easy to change the posture of the body. Divide it into two small bags, ~ one shoulder, one handheld, to disperse the weight. 4, when buying a bag put a book to try to carry 3 minutes? When buying a bag first put a book in the bag, let the bag a little weight, try to carry 3 minutes to see how comfortable the shoulder, as well as the size of the contact surface of the bag with the body, the degree of fit, etc.. Try to choose the size of small, wide back.