Knee braces: pros, cons and how they can help runners
I observed several people wearing some form of a knee brace recently. I saw several runners at races with similar knee wraps. I wore a rubber knee sleeve for a few runs. It was a snug fit around the knee with a hole in the middle for the kneecap. I started to think about any advantage this knee sleeve was actually accomplishing. My reason was I had no cartilage in my right knee and on runs this would cause the bursa in my knee to leak a little and cause my knee to swell up. The sleeve kept pressure on the knee and helped reduce the amount of swelling after a run. It worked well enough that I wore it for several months.
What individuals need to know is that there are only very few knee braces that actually give support to the knee joint. The braces that football players wear with metal strips down the side and straps holding them in place can actually help prevent the knee joint from moving sideways where it is not meant to move. The knee is a hinge joint and only moves forward and backward. If it moves in any other direction it is a good indication that something is broken. Athletic trainers have a few tests they perform on injured athletes to see if the knee is injured. With the leg held straight they try to move the lower leg from side to side. If the lower leg moves to the outside it means the medial collateral ligament is probably torn. If it moves to the inside it means the lateral collateral ligament is torn. While sitting the athlete down, they try to pull the top of the lower leg forward. If it moves forward an inch or so it means the anterior cruciate ligament is torn. If they push in on the top of the lower leg and it moves backward that is an indication that the posterior cruciate ligament is torn. There are more than these four ligaments surrounding the knee but for quick and easy assessments these four tests give the athletic trainer an idea of how severe the injury is. The point of this anatomy lesson is that unless the brace is a special design it will not prevent movement of a knee joint. It can reduce swelling somewhat but offers no support to prevent movement.
The knee is an amazing joint and has ligaments and muscles to hold it in place. With strong muscles adding to support of the knee it usually lasts for a long time. Basic muscle structure has the four quadriceps muscle in front of the thigh and three major hamstring muscles in the back of the leg. The lower leg has the major gastrocnemius (calf) muscle cross the knee joint to lend a little support also. Between these muscle groups and ligaments the knee is a solid joint. If this is so, then why is the knee one of the major injuries and problems for athletes and runners? The leg is a long lever and any strong force to the joint can cause an injury. Another problem is that the athlete or runner has a muscle imbalance in the leg muscle that causes the knee cap to be pulled out of line. For a large majority of athletes the quadriceps are about four times stronger than the hamstrings. The only athletes I have found with equal strength between these two muscle groups were with professional hockey players.
The four quadriceps muscles can also cause a problem. There is a muscle on the inside, one on the outside, one on top and one underneath giving strength to move the lower leg forward. The problem is often the muscles are not of equal strength. If the outside muscle is stronger than the inside muscle, the kneecap is pulled over to that side. There is a groove on the knee that is designed for the kneecap to follow. If it is pulled to the side, the underside of the knee cap rubs on the edge of that groove. This causes a tear in the tendon that encloses the kneecap and it hurts. It is usually most notable when the runner is walking downstairs and a sharp pain occurs with each step. It is usually the lateral (outside) muscle that is stronger than the medial (inside) muscle. For this problem the knee sleeve brace with the hole in the middle helps keep the kneecap moving in the right direction. If the runner needs to strengthen the inside quad muscle an easy exercise is the thigh extension movement from a 45-degree angle to extension. A full range of motion strengthens both muscles and you are trying to get the muscles at equal strength. Once they are equal strength the full range of motion can be done.
The knee is a remarkable joint and has the anatomy to stay healthy by itself. It is outside forces or muscle imbalances that often cause problems. Understanding the anatomy of the knee helps.
