Let’s talk about knees. They are pretty cool. They allow you to runs, jump, sit, climb, skate, and basically do everything except walk on your hands. Without them, your daily life would be monumentally different. The thing about knees is, they are not indestructible. Over time knees can wear down, just like the tires on a car. However, unlike the tires on a car, you cannot go out and buy a new knee. The two you are given are the two you get, so it’s probably best to make them last.
Knee injuries are extremely prevalent in sports, and a knee injury can quickly ruin careers. We’ve all seen the Marcus Lattimore injury (if not, you can watch it here – be warned, its graphic), and while your knee injury may not be as bad as his, it’s best to avoid it all together. Read the tips below and better understand how to take care of an integral part of your body, life, and sports career.
I talk a lot about form when coaching, and while this should be no surprise (after all, I am coaching), I do not coach form just because “it’s how the exercise should be done.” I specifically focus a lot of my attention at the knee joint and ankle joint. When protecting the knees and keeping them healthy, the name of the game is joint angles, specifically the ankle joint angle. During lower body pushing exercises, think squatting and lunges, the joint angle at the ankle should be in the range of 90° of flexion, to an angle that does not place the knee in front of the metatarsals – the middle toe bone. This end angle of flexion is typically around 70° and not more than 60°.
When our ankle flexion is too great (<60°), the force required to push away from the ground is routed through our knees at an angle that does not allow our thigh and shin to work together. Instead, our femur (thigh) receives more of the force and therefore pushes forward on our tibia and fibula (shin bones). This occur because the hamstring muscles cannot engage at such a high joint angle. The ligaments in our knee – ACL, PCL, MCL, and LCL, are then responsible for holding our femur in place so that it does not slide forward. This becomes a problem because those ligaments cannot support the force that our muscles can. When the force becomes too great, those ligaments tear, and you become injured. Keeping your ankle joint angle closer to 90° allows the hamstring to engage and take a large amount of force off the knee ligaments. The force is also transmitted through the knee at an angle that better allows the thigh and shins to work together to create the desired movement.
2. The Popliteus Muscle
The what? The popliteus muscle is a small muscle on the back side of your knee. It is responsible for rotating the tibia inwards, allowing the knee to bend from a fully extended (straight) position. It also is responsible for pulling the tibia posteriorly (backwards) during knee flexion, which clears room for the meniscus to not be crushed during knee flexion. For those wondering, the meniscus is a piece of cartilage that acts as a pad between the thigh and shin – and there are two of them at the knee joint, a lateral and medial meniscus. All together this muscle helps to keep the knee moving properly, and care should be taken to make sure the muscle is healthy, as it endures a heavy work load each day. Take time to roll out, with a softball or lacrosse ball, the back of your knee and keep the popliteus working correctly.
This tip may seem like a no brainer, but it is important. Having the correct flexibility will keep muscles healthy, and in turn the knee healthy. A tight muscle is not able to contract as strongly as a normal resting length muscle, causing the force to be displaced during exercise, and resulting in possible unneeded stress on the knee. Make sure the hamstrings, quads, glutes, calves, and hip muscles all have proper flexibility. Take time to stretch after workouts, and foam roll before and/or after workouts. A few minutes a couple times a week could save a few years of your athletic career.
Fatigue is one of, if not the most common reason for injury. When your body is tired, your muscles cannot create the force they are able to when rested. Your sport, along with your competitive drive, could care less about this and continue to place you in situations that require high force outputs. When your muscles cannot supply the correct force, something has to give. Most of the time this is your knee ligaments. Get yourself in shape, and make yourself stay in shape. It will not only allow you to perform better, but it will keep you off of the IR. As a bonus, better cardiovascular conditioning means better recovery during and after competition and better recovery from injuries.
Your knees are like that brand new BMW you bought however many years ago. Treat them well and they will treat you well.