One of the most common ailments that plague athletes in many sports, well, beside Ping-Pong, is the knee injury.

We all know that Vince Carter had one for the majority of last year’s NBA season, and that Toronto Maple Leaf tough guy Darcy Tucker sent the Islander’s Mike Peca on a sabbatical from the NHL playoffs with a hip-check to the knee. But many people don’t understand the complexities and dangers of knee injuries.

The risk of knee injuries is greater in some sports mainly due to their nature. For instance, football players are very likely to sustain damage to their knees because tackling is an integral part of the game. Similarly, ice hockey players move very fast on an unstable surface while trying to avoid being hit by opponents. The speed combined with the ferocity of body checks leads to serious, sometimes career-ending injuries.

The knee is the largest joint in the body and is vital to movement. Two sets of ligaments in the knee give it stability: the cruciate and the collateral ligaments. The cruciate ligaments are located inside the knee joint and connect the thighbone (femur) to the shinbone (tibia). They are made of many strands and function like short ropes that hold the knee joint tightly in place when the leg is bent or straight. The cruciate ligament located toward the front of the knee is the anterior cruciate ligament (ACL), and the one located toward the rear of the knee is called the posterior cruciate ligament (PCL).

Injury to the ACL is very common among hockey, football and basketball players. It can be injured in several ways including changing direction rapidly, slowing down when running, landing from a jump, or from direct contact such as a body check.

After an ACL injury is sustained, the knee will swell up and standing up will cause pain. An X-ray or MRI is used to spot tears in the ligament. If the tear is a significant one, a surgeon will have to operate on the knee, which could be potentially career ending for an athlete.

The recovery from an ACL injury can be long and painful, one, with months of physiotherapy. With smaller tears, rest is usually the best treatment.

Another very common type of knee injury occurs in the collateral ligaments, which are located at the inner side and outer side of the knee joint. The medial collateral ligament (MCL) connects the thighbone to the shinbone and provides stability to the the knee.

Most professional athletes are aware of the risks that come with sports and the fragile nature of the human body under the intense pressure of athletic competition. They train to beat the best, but always prepare for the worst. Many spend hours training and working small stabilizing muscles that are susceptible to injury.

Athletes hope that an ounce of prevention becomes a pound of cure.