The knee is the joint found in the medial region of the legs and also considered the most complex of thier biomechanics, however, in functional terms one of the simplest (KARPANDJI, 2000).

This joint is composed of three bones: the femur, tibia and the patella. Due to its asymmetry between the medial and lateral and the anterior surface of the patella, it generates bearings when we flexion and knee extension (KISNER, 2005).

Complex and fine structure and a perfect machine, the knee joint is formed within the synovial capsule medial tibiofemoral joint, lateral tibiofemoral and patellofemoral. The tibiofemoral joint so as medial side works like a hinge, with two menisci supported by ligaments and muscles. The anteroposterior stability is of the cruciate ligaments, the medial collateral ligament (tibial) and lateral (femoral) are responsible for mediolateral stability. The patellofemoral comprises the patella within the quadriceps tendon (HAMILL and KNUTZEN, 1999).

       The movements are allowed in this joint extension, flexion and rotation. The extension and flexion occur by the sliding of the tibia in the sagittal plane earlier in extension and flexion later. The rotation is a movement that only occurs when the knee is flexed, then, with the extension to be contracted muscles preventing movement (SMITH, 1997).

       The medial and lateral menisci are fibrocartilagens whose function is to ensure harmony of the articular surfaces and cushion pressure (KISNER, 2005). The medial collateral ligament is located on the inside of the knee and provides resistance to movement in valgus (inside or medial), and a support function in the rotation movements (HAMIL and KNUTZEN, 1999). Have the lateral collateral ligament is located as the name implies, knee-side and offers resistance to movement in varus and adduction of the tibia. Ligaments responsible for the harmony between tibia and femur, the anterior and posterior cruciate ligaments (ACL and PCL, respectively), limits the sliding of the tibia, the LCA preventing it make previous movements and the LCP running later movements in relation to the femur (KANPANDJI , 1987; Smith, 1997; and HAMILL Knutzen, 1999).

       The knee being located between the hip and the ankle suffer much influence of irregularities and imbalances occurring in these joints and tissues that surround it.

Now that we know about the knee joint, stay tuned, soon we’ll talk about the dysfunctions and knee injuries.

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