Knee Anatomy and Function
The knee is the largest joint in our body and is formed by the union of two fundamental leg bones: the femur and the tibia. Additionally, it features a small bone called the patella (kneecap) and two fibrocartilaginous discs known as the menisci.
It is through the muscles surrounding the knee that we can perform movements such as walking or running. The knee bears most of our body weight when we are standing.
This joint is also composed of ligaments that prevent dislocations. The knee is vulnerable to serious injuries from trauma, generally caused by sports activities that generate high impact and undesirable rotations in many cases.
The development of osteoarthritis is also common and may require surgical intervention. Without a doubt, the knee is a very complex and important joint, requiring early care and attention when injuries or pain complicate the performance of a normal life.
Where the femur and tibia meet, we find "shock-absorbing pads" called menisci, which prevent the bones from rubbing and absorb the pressure generated by movements like jumping, preventing other parts from wearing out or being affected. As the knee constantly bears our weight, it has different ways of protecting itself through tissues and structures that make it more resistant to pressure and friction, such as the prepatellar cartilage between the patella and femur, or the synovial membrane, which produces synovial fluid that acts as a "lubricant" between the different moving structures of the knee.
Ligaments and tendons play a fundamental role in stabilizing the knee. For example, the patella is embedded in the quadriceps tendon and connects to the tibia via the patellar ligament below, creating a "bridge" that allows extension and tension movements. We also have lateral ligaments: the medial one joins the femur and tibia and prevents the knee from deviating inward, and the lateral one runs from the external femoral condyle to the fibular head and prevents the knee from deviating inward.
Other more famous ligaments are the cruciate ligaments, both anterior and posterior, although the former is more recognized as its injuries or tears are more frequent on the playing field. They are responsible for fixing the femur and tibia and prevent them from moving beyond their limits. They are located inside the knee; the anterior one is further forward and slightly thinner than the posterior one, making it more prone to injury.
The knee gains its strength from the powerful muscles in the thigh, especially the quadriceps, whose main mission is knee extension. It is completed by other muscles such as the semitendinosus, semimembranosus, femoral biceps, and gastrocnemius (calves), all responsible for knee flexion.
