põlveliigest

The põlveliigest, or knee joint in English, is a complex hinge joint in the leg that connects the thigh bone (femur) to the shin bone (tibia). It is one of the largest and most structurally intricate joints in the human body, crucial for locomotion, weight-bearing, and shock absorption. The knee joint is composed of three bones: the femur, the tibia, and the patella (kneecap). The patella sits in front of the femur and articulates with a groove on its surface.

The joint is surrounded by a capsule and reinforced by several ligaments that provide stability. Key ligaments include the anterior and posterior cruciate ligaments, which cross each other inside the joint and prevent excessive forward or backward movement of the tibia relative to the femur, and the medial and lateral collateral ligaments, which run along the sides of the knee and prevent excessive side-to-side motion. Two C-shaped pieces of cartilage, the medial and lateral menisci, act as shock absorbers and smooth surfaces between the femur and tibia, allowing for better weight distribution. The joint is lubricated by synovial fluid, which reduces friction between the articular cartilages covering the bone ends.

The primary movements of the knee are flexion (bending) and extension (straightening). Rotation of the tibia on the femur is also possible when the knee is flexed. The knee joint is susceptible to injuries due to its weight-bearing function and the stresses it endures during activities like running, jumping, and sudden changes in direction. Common injuries include ligament tears, meniscus tears, and osteoarthritis.