A knee sprain from squatting up may be a lateral collateral ligament injury, cruciate ligament injury, etc. Treatment includes non-surgical treatment and surgical treatment. 1. Lateral collateral ligament injury: Simple lateral collateral ligament strain should be immediately cold compresses, compression bandage, according to the situation with physical therapy, such as microwave, electrotherapy and so on. If the lateral collateral ligament is ruptured, it should be fixed by surgical suture. 2. Cruciate ligament injury: For minor partial injury, the knee joint can be immobilized by plaster or brace. If there is a rupture of the cruciate ligament, reconstruction surgery should be performed in time. If the symptoms of knee sprain are serious, it is recommended to go to the hospital in time to find out the condition of the injury and have regular treatment.