A randomized controlled clinical study was conducted to elucidate the relationship between the lower extremity biomechanics of patients undergoing early gait training after ACLR surgery.The relationship between the biochemical characteristics of cartilage and the biomechanical risk index were proposed to providing exercise guidance and training for ACLR people and it is suggested that it can prevent and reduce the risk of cartilage degeneration early after operation.

In this randomized controlled clinical study, patients with primary unilateral ACL rupture were included. In addition to standardized rehabilitation training content, gait training intervention under weight loss was added to the subjects in the early postoperative period. The control group only received standardized rehabilitation training. Based on motion testing and dynamic analysis, the influence of early postoperative gait training on postoperative gait biomechanical characteristics was explored. And the influence of early cartilage health status; Based on functional MRI, the effects of early postoperative gait training on biochemical parameters of knee tibiofemoral and patellofemoral cartilage were investigated.

Inclusion Criteria:

1. Patients with ACL rupture were diagnosed by MRI;
2. Unilateral ACL rupture for the first time should be performed in our hospital (Department of Sports Medicine, Peking University Third Hospital)The art of reconstruction;
3. Normal BMI range: 18.5-23.9 kg/m2;
4. Within 6 months from the trauma;
5. The affected knee joint has passed the acute stage, no obvious redness, pain,inflammation, and limited joint motion,basically restore joint motion.

Exclusion Criteria:

1. BMI<18.5 kg/m2 or BMI≥24 kg/m2);
2. There is a history of contralateral lower limb musculoskeletal system injury and surgery;
3. ACL injury time > 6 months;
4. Outerbridge damage rating Ⅲ and Ⅳ;
5. Patients with meniscal tears who are expected to undergo meniscal suture surgery at the time of ACLR surgery;
6. Serious injury to the posterior cruciate ligament, medial collateral ligament, or lateral collateral ligament;
7. There is metabolic syndrome (obesity, dyslipidemia, diabetes, etc.), which will involve articular cartilage Epidemic diseases, serious cardiovascular and cerebrovascular diseases, etc.;
8. Those who do not want to accept this treatment