The Knee - Part 1 (Anatomy)
By Laurie Sweig
Published July 19, 2018
Raise your hand if you have suffered from knee pain or a knee injury. Almost every client I have seen over the years has experienced an issue at one time or another with one or both knees. I have been part of that group but I’m thrilled to say that I’m enjoying being free of knee pain for the moment.
The knee is a complex joint. Basically speaking it joins the thigh bone (femur) with the shin bone (tibia). The two other bones that make the knee joint are a second shin bone (fibula), and the kneecap (patella). Keeping all of these bones working together are tendons and ligaments. Tendons connect muscle to bone, and ligaments are the connection between the bones.
Here’s a breakdown of the ligaments of the knee joint:
The anterior cruciate ligament (ACL) prevents the femur (thigh bone) from sliding backward on the tibia (shin bone).
The posterior cruciate ligament (PCL) prevents the femur from sliding forward on the tibia.
The medial and lateral collateral ligaments (MCL and LCL) prevent the femur from sliding side to side.
There are two major tendons in the knee joint. One attaches the quadricep muscles (front of thigh) to the kneecap (patella) and is responsible for straightening the leg and keeping the kneecap in place. The other tendon attaches the kneecap to the shin bone.
Where bones come together like they do in the knee joint there is cartilage. Cartilage is a white, smooth, fibrous connective tissue that protects the bones when the joint moves. The ends of the femur, top of the tibia and the back of the patella are all covered in this cartilage. There is additional protection in the form of disc shaped cushions that act as shock absorbers between the femur and tibia. They are the medial and lateral menisci.
Working with the cartilage to keep the knee joint functioning is synovial fluid. The combination of the two creates a slippery surface that is three times more slippery than a sheet of ice. The human body is amazing!
Providing the last bit of protection are fluid-filled sacs called bursa. There are 13 bursa sacs located in and around the knee that cushion the joint and reduce friction between muscles, bones, ligaments and tendons. The most significant is the one located at the front of the knee. It is there to protect the kneecap.
All of this engineering is essential because the knee joint bears most of our body weight. Even with all of the protective measures the knee is still vulnerable to the use and abuse we put it through. If “knowledge is power” then learning more will help us to keep our knees healthy and happy.
Something to think about.
Laurie Sweig is a certified personal fitness trainer and spinning instructor. She owns and operates The Point for Fitness. She can be reached at firstname.lastname@example.org.