A large number of cases show that, according to the traditional practice, after several months of postoperative recuperation, the injured person is immobilized for too long and many complications occur, such as joint swelling, tissue adhesions, muscle atrophy, decreased joint mobility, and even loss of joint motion. It is often seen that after the immobilization of the affected limb is opened, the patient cannot even do normal bending movements. Therefore, the first thing they have to do is to release the adhesions of the soft tissues of the joint by pressing the joint open, which looks simple but is time-consuming and painful, and the patient often cannot help but scream. Some people even give up the previous surgery in order to avoid this post-operative pain. Moreover, if the rehabilitation method is not appropriate at this stage, it will make the rehabilitation period longer. Modern rehabilitation concepts and methods can effectively avoid these consequences of traditional practices. It advocates timely joint mobility training before the soft tissues of the injured part adhere after surgery to keep the muscles active and to lay a good foundation for the resumption of normal activities and even sports in the future, and, at the same time, to save time and improve the efficiency of rehabilitation. In many countries, this concept and method is not only adopted in the sports world, but also widely used in the daily rehabilitation of the people. In U.S. hospitals, not only are there rehabilitation specialists in every department, but active rehabilitation activities often begin as soon as the patient returns to the ward from the operating room. For example, after a joint replacement surgery, the rehabilitator will place a “continuous passive motion device” on the patient’s surgical site to help the patient move around to avoid adhesions in the soft tissues of the injured area. Even for patients in the endangerment unit, the rehabilitators go over and help them do various exercises to move their stiff joints and prevent blood clots from forming. In their view, rehabilitation is exercise. In order to recover early, one has to exercise early. When should active rehabilitation be early? This is determined by the site of injury and surgical method, as well as the individual’s physical condition, and must be implemented safely and effectively under the individualized guidance of a specialist physician and experienced rehabilitator. Some active recovery methods can be used after the anesthesia has worn off, while after ACL reconstruction surgery, the injured person needs to start moving again after the ligaments have grown strong. Finally, it should be noted that: 1. Active postoperative rehabilitation is also closely related to active preoperative preparation. For example, patients should try their best to minimize the swelling of the affected part before surgery, maintain the strength of the affected part and the mobility of the joints, and undergo surgery in such a physical condition that can reduce postoperative complications and accelerate recovery. 2. Active rehabilitation exercises depend on others in three parts and on yourself in seven parts. After all, the guidance and help from doctors and rehabilitators are limited, and most of the time, we have to rely on ourselves to persistently and strictly follow the requirements of exercise, and have a healthy life style and exercise habits to cooperate, which also requires personal perseverance and self-awareness to guarantee.