This study investigates the effects of plyometric training with blood flow restriction on muscular strength, quadriceps thickness and knee joint function in patients with muscle weakness and atrophy (quadriceps muscle and hamstring muscle) after anterior cruciate ligament reconstruction. Persons who completed a 12-week routine rehabilitation program after anterior cruciate ligament reconstruction will be included in the study. In the study group, plyometric exercises will be performed with blood flow restriction in the operated side for 8 weeks. In the control group, the same plyometric exercises will be performed without any application.

Anterior cruciate ligament (ACL) rupture is one of the most common sports injuries. Surgical procedure is usually performed after injury. After ACL surgery, patients experience problems such as pain, impaired knee function, and especially quadriceps muscle weakness and atrophy. Quadriceps atrophy has been shown to persist for years despite rehabilitation programs. Therefore, rehabilitation programs after ACL reconstruction play an important role in ensuring return to sports and reducing postoperative complications. In general, ACL rehabilitation can be divided into early and late periods. In the early period, while focusing on the solution of the primary problems related to the knee (pain, edema, joint movement limitation, quadriceps muscle weakness, and antalgic gait), the focus is on the patient's preparation for returning to sports activities. Running, jumping and agility training are the exercise approaches of late phase rehabilitation. These exercises include pliometric activities that trigger the stretch-shortening cycle of the lower extremity extensor muscles. Pliometric exercises after anterior cruciate ligament reconstruction may improve lower extremity muscle strength and knee function and increase the rate of return to sports, but there is not enough study in this area. Under normal conditions, 6-12 repetitive weight-lifting exercises at a density of at least 65% of a maximum repetition are recommended to increase strength in a muscle and achieve hypertrophy. However, it takes approximately 4-6 months for the ligament to mature and bear weight after surgery. For this reason, high intensity strengthening training is not used in the early period of rehabilitation to protect the graft that is recovering after surgery and the training is started from low intensity and increased gradually. Recent studies suggest that muscle hypertrophy occurs with low-intensity exercises (20-30% of a maximum repetition) with blood flow restriction, also known as KAATSU training or occlusion training. Because blood flow restriction training allows the benefits of high intensity training to be obtained at a much lower intensity. In the literature, the effectiveness of many different exercise programs after ACL reconstruction was investigated. However, no study investigating the effect of blood flow restriction plyometric exercise training on ACL rehabilitation on muscle strength and function was found. This study will be conducted to investigate the contribution of low-density plyometric training with blood flow restriction to atrophy, muscle strength, function and return to sports.

Inclusion Criteria:

• Age between 18-45 year
• Volunteering to participate in the study
• Patients who had unilateral anterior cruciate ligament surgery with hamstring tendon auto graft and completed 12 weeks of rehabilitation program

Exclusion Criteria:

• Systemic or neurological problems
• Endothelial dysfunction
• Peripheral vascular diseases and history of deep vein thrombosis
• Active infection, cancer, pregnant,
• Posterior cruciate ligament tear, medial or lateral collateral ligament tear and knee cartilage damage

There is not a plan to make IPD available