The specific walking time for a torn collateral ligament needs to be judged according to the severity of the injury and the recovery situation, and cannot be generalized, generally 4~6 weeks can walk. A collateral ligament tear is usually caused by direct trauma or indirect violence, which can result in a partial tear of the ligament in mild cases, or a complete rupture in severe cases. In mild cases, the ligament can be immobilized with a plaster cast, which can be removed in 4-6 weeks, and then the knee joint can be flexed and extended, and then the knee joint can be gradually moved down to the ground for exercise. In severe cases, surgery is needed to repair and reconstruct the knee, and the knee needs to be immobilized for about 4~6 weeks after the surgery. During the recovery period, even though you can’t go down to the ground, you can still do rehabilitation exercises, such as muscle contraction exercises, ankle pump exercises, straight leg raising exercises, etc. You also need to visit the doctor regularly for review. Regular checkups are also needed, and the exact time to go down to the ground needs to be judged by the physician according to the condition of recovery.