Close to the impossible is the ultra-difficult action of close to the impossible. Hold the lever horizontally with your arms and keep your body upright in the air. With the help of cti, the requirements for triceps brachii, latissimus dorsi and deltoid muscles are extremely high, ranking third in the street health extreme movements. Cti without external force violates the laws of physics, but theoretically it can be done if the grip strength is strong enough. At present, no one can make a standard unaided cti, but they all lean forward and can't stand straight.