Have you ever felt a creak in your knees in the middle of a long run? Or maybe a slight clicking as you squat or walk down a flight of stairs? Well, you're surely not alone: An injured knee is one of the most common reasons people visit the doctor. While there are multiple causes of knee pain, recent research and clinical findings have uncovered methods to help prevent all types of knee joint injuries.
Inside Your Knee
The knee is composed of two joints: one between the thigh bone (femur) and leg bone (tibia) and one between the thigh bone and kneecap (patella). Between the thigh bone and leg bone lie two crescent-shaped pieces of cartilage, called menisci. Adding to the anatomical elegance of the knee are fluid sacs (bursae), tendons, ligaments, and muscles.
The knee functions like a hinge joint, meaning that movement is primarily along one axis: to flex or extend. There is also slight rotational and bending movement.
Common Causes of Knee Pain
Knee pain is often the result of repetitive strain caused by overuse and further induced by improper movement patterns. Let's look at four common knee injuries:
- Patellar tendinitis (jumper's knee). The patellar tendon connects the kneecap to the leg bone. Accordingly, patellar tendinitis is characterized by inflammation and pain to this region and is most common in athletes who participate in jumping sports. It is caused by repetitive overuse of the tendon and is referred to as tendinopathy if it becomes a chronic condition.
- Meniscus tears. A meniscus tear is when one or both of the pieces of cartilage between the thigh bone and leg bone tear. The telltale signs of meniscus tears are pain, swelling, an inability to straighten the knee, and/or a feeling of clicking within the knee.
- Sprained ligaments. Ligaments are fibrous tissue that connect bones together. Their primary purpose is to provide stability. A sprain is a stretch or tear to a ligament. There are four major ligaments in the knee: the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL). Because each ligament serves a unique function, the potential cause for strain is similarly unique. The commonly torn ACL, for instance, controls rotation and forward movement of the leg bone relative to the thigh bone; the cause of ACL tears is often hyperextension while pivoting. Needless to say, a sprain of any of these four ligaments compromises the stability of the knee joint.
- Runner's knee. Runner's knee is a catch-all term for overuse injuries that lead to knee pain. Runner's knee may actually refer to patellofemoral pain syndrome (pain in the front of the knee), iliotibial band syndrome (pain derived from lateral motion), or chondromalacia patella (pain and inflammation to the underside of the kneecap).
Despite the complexity of knee joint injuries, there are a few simple actions you can take to prevent injury:
- Work on those hips. Abnormal hip mechanics is considered a big contributing factor of knee injuries. The logic is simple: If the hips are weak, the knees will tend to fall inward; this results in increased pressure on menisci and higher strain on the MCL, as well as abnormal kneecap alignment.
- Focus on function for the relevant activity. It doesn't make much sense to focus on isolated leg exercises if you're a soccer player, does it? What you need is neuromuscular training to help prepare your knee for the demands of the sport. Similarly, if you're a basketball player, proper mechanics during jump training, including landing with a wide base of support and preventing your knees from falling inward, is hugely important.
- Stretch. It should be no surprise that improving your flexibility helps decrease overuse injuries. Essentially, having the proper flexibility allows your joints and limbs to move as they should. Stretch out those quads and hamstrings, and invest in a foam roller.
- Follow instructions. There are numerous preventive and rehabilitative protocols for various knee injuries. Remember, your doctor or physical therapist is your friend and can guide you on the road to full health.
Although knee injuries are common, simple and consistent exercising will go a long way toward cutting down injury risk. So get in the gym, strengthen those hips, develop your flexibility, and focus on activity-specific training. And don't be shy about asking your doctor for some advice along the way!