The knee is a joint that, due to its function, is susceptible to injuries that can be interconnected, but also isolated. The most common types of injuries are muscle and ligament sprains, ruptures, with rupture of the anterior cruciate ligament as the most common. Most ruptures occur without a contact, by falling or sudden movements that cause hyperextension or rotation of the knee. The injury itself is accompanied by intense pain, swelling and possible appearance of hematoma in the knee. Before the surgery, a cold compress is placed on the knee, a compress of the elastic bandage and the person should rest in order to reduce pain and swelling. Also, in order to confirm the type of injury, tests such as the anterior drawer test, Lachman test and Pivot shift are performed, whose function is to show whether there is an increased tibia displacement compared to other knee structures and thus confirm the occurrence of ACL rupture. Surgery is followed by rehabilitation for 6 months, which is divided into 4 stages. During this period, the function of the joint is restored so that the patient can once again participate in the activities of daily life. Mobility and coordination are developed, a proper walking pattern is learned, musculature is strengthened and a person is gradually prepared for heavy joint loads. If it is an athlete, specific sports activities are introduced during the fourth phase so that at the end of the rehabilitation he is fully ready to return to sports. The completion of the rehabilitation process represents a preventive period in which a person independently conducts kinesitherapeutic exercises already learned during 6 months, in order to prevent the recurrence of the injury.