According to Angela, D, Smith, MD, Stanley, S, and Tao, MS. (July 1995.) Knee Injuries In Young Athletes. Philadelphia, PA. W. B. Saunders Company, in most childhood sport, knees are frequent sites of injury. The knee injuries are very common in some kind of sports such as soccer, football, and basketball. Soccer is the most kind of sport that has a big number of knee injuries. The knee damaged needs a surgery and physical therapy to fix. A lot of players cannot play soccer for about six months after doing the surgery. The most common knee injury is the ACL. ACL is that the anterior cruciate ligament which is one of four ligaments in the human knee. The anterior cruciate ligament is located on the knee, which connects the two legs together Children who get knee injured might grow up with knee problems. Why children who have done a knee surgery could have a knee problem in the future? The knee could be fixed for children, but they might have a problem when they are adult. There are some doctors who do not like children to have a surgery while they are young. Why doctors prefer doing the surgery for children when their bodies stop growing up?  The reason why doctors do not like the children to have a knee surgery while they are young is because they might have the same injury when they are adult which is called reinjured

The best way to avoid knees injuries is protecting them. Why soccer players do not protect their knees before they get hurt? In order to protect the knee, players should wear some knee braces. According to (A lightweight brace that provides complete ACL protection), the DonJoy Full Force knee brace is the one of the most powerful brace to protect the ligament of the knee. It might not totally protect the knee from injuries, but it could make the injury not so bad. There is a lot of bad player friction during the match, so the brace cannot protect the knee from injuries. In that case, the player should be careful with that situation. They are a lot of good ways to protect the knee such as training and wearing knee braces. According to Prevent Common Injuries in Soccer: Knee Injuries (May 22, 2009,) there are some of training programs that help to make the knee strong enough and could be the reason to avoid some injuries. Warming up, and agilities are the some programs that help the knee to be safe. Warming up includes zigzag run back and forth across the field then jog backwards. Agilities are easy for the player, which means shuttle run forward and back, diagonal runs, and bounding run.