Anatomy For Runners: The Knee

Welcome to my Anatomy For Runners series! With this I’m hoping to educate runners on their bodies so that they feel more empowered in staying healthy. Don’t worry, we’ll keep it light, fun, and focused on what you really need to know with a bias toward the runner’s body.

This second installment is all about the knee. So, you could say, we’re going to go over everything you “kneed” to know about this joint and why Aunt Margie is wrong when she says you’re going to ruin your knees as a runner.

The knee joint is classically known as a “hinge joint”, meaning that it moves in two directions, similar to a hinge on a door. There is a tiny bit of rotation that occurs here as well, and as we’ll learn in the coming paragraphs, it’s important to be able to control that rotation as the miles pile up.

The knee is the interface where the femur and tibia meet. The fibula is adjacent to the tibia, but does not articulate with the femur in the way the tibia does. Both the tibia and femur are cushioned with cartilage - a dense connective tissue that helps with shock absorption. On top of the tibial cartilage sits the meniscus, a structure many of you may be familiar with. The meniscus helps improve the fit of the joint and guides movement. There are two aspects of the meniscus, the medial (inner) and lateral (outer) portion. The bones of the knee joint are connected together by several ligaments, which we won’t get into much detail about, as they are not commonly injured in runners unless a trail or obstacles are involved. The patella, or knee cap, has no direct articulation with another bone and is both held in place and influenced by the quadriceps. The four muscles form a common tendon that attaches to the top of the patella, and then progresses to create the patellar tendon (you know, the tendon that your doctor hits with the reflex hammer). Finally, the knee joint is surrounded by a capsule which is a connective tissue that wraps around it sort of like Saran wrap.