The collateral ligament generally refers to the medial collateral ligament of the knee joint. When injured, it can be recovered through braking, ice packs, elevating the affected limb, and rehabilitation exercises. In the acute stage of collateral ligament injury, you can stop exercising immediately, use ice packs to reduce local swelling, and elevate the affected limb to promote venous return to reduce swelling. After the acute stage, rehabilitation exercise can be carried out, mild injury can be fixed in a brace, gradually carry out knee extension and flexion movements, and then gradually help the crutches to walk on the ground, to walk on the ground normally, after six months can be completely normal activities. After surgery for serious injury, early cast immobilization, can carry out some muscle isometric contraction exercises near the joint, after removing the cast, feasible flexion and extension joint training, and gradually transition to walking on the ground with crutches and normal walking on the ground. After the injury of collateral ligament, it is recommended to seek medical treatment in time, under the guidance of doctors for treatment and recovery.