Even though sport as a physical activity has positive physiological health effects on the human body, it is important to emphasize that the number of injuries in pro athletes caused by doing sports professionally has doubled in last 3 decades. Training too strenuously, the overtraining syndrome, as well as pushing the organism to its physiological limits can all lead to the injury that I further describe, which is the main reason why more and more people associate sports with injuries, instead of health. Anterior cruciate ligament (ACL) injury can be dangerous, and its treatment is complicated and challenging. With the advancement of medicine, new ways of ACL rupture reconstruction via the semitendinosus tendon have been developed, making the surgical process simpler and safer. For this reason, more people are opting for surgical treatment methods, but the postoperative rehabilitation process still remains long and tiring. According to some statistical data, ACL rupture is one of the most fragment knee injuries, affecting around 85 in 10,000 individuals aged 16 to 39 years. As it mentioned above, the reason for this injury in professional athletes are mainly training too hard, overuse syndromes, or excessive stress placed on the entire body, while in recreational athletes, it is the result of insufficient preparedness. For these reasons, I have chosen the topic "Rehabilitation after anterior cruciate ligament surgery," in order to describe the complexity of the surgery as well as the rehabilitation process to myself and others. Within rehabilitation three are two phases, the preoperative and postoperative phase of treatment, the whole process takes about six months and mainly consists of kinesiotherapy. Muscle deficits can be felt up to three years after the injury. As for other deficits, the static and dynamic stability of the joint are compromised due to damaged proprioceptive signals in the joint.