Knee Injuries

:kidshealth.org

2012/02/27

936

If you've ever had a knee injury, you know that you need healthy knees for many activities and sports, and that getting hurt can mean some time sitting on the sidelines. Fortunately, there are ways you can prevent knee injuries.

What's in a Knee?

To understand knee injuries, first you have to understand the knee. The knee is a joint, which means it sits between the area where bones connect. It's actually the largest joint in the body. Your knees provide stability and flexibility for your body and allow your legs to bend, swivel, and straighten.

The knee is made up of several body parts like bones, cartilage, muscles, ligaments, and tendons, all working as one. So when we talk about a knee injury, it could be stress or damage to any of these parts.

Bones and Cartilage

The knee sits in the middle of three bones: the tibia (your shin bone), the femur (your thigh bone), and the patella (the knee cap). The patella is a flat, round bone that protects the knee joint.

The ends of the femur and the patella are covered in articular cartilage (think of the white stuff at the end of a chicken bone). Articular cartilage acts like a cushion and to keep the femur, patella, and tibia from grinding against each other. On the top of the tibia, extra pads of cartilage called menisci help absorb the body's weight (if you're talking about one, it's called a meniscus). Each knee has two menisci — the inside (medial) meniscus and the outside (lateral) meniscus.