The Anatomy and Actions of the Knee Essay -- essays research papers

The stifle joint is formed by the articulation of the distal end of the femur and the proximal end of the tibia. The fibula is only pertain to the extent that it serves as an seizement site for connective tissue. In this paper, the anatomy of the joint will be discussed. The knee is a hinge-type, diarthrotic, or freely moveable joint. Also referred to as a synovial joint, the 2 articulating ends of bone argon encased in a capsule that lubricates the joint with synovial fluid to sign friction.Each bone in a synovial joint has articular cartilage at the articulating surface. The C-shaped median(a) and lateral menisci serve to deepen the articulation at the superior surface of the tibia, thus enhancing the bony stability of the joint.Also adding to the joints stability argon the two major pairs of ligaments the cruciates and the collaterals. The medial and lateral collateral ligaments have a stabilizing effect in a lateral plane of motion, helping to prevent sideward displacement and over-rotation. The medial collateral attaches the femur to the tibia, also attaching to the medial meniscus. The lateral collateral attaches the femur to the fibula but has no attachment to the lateral meniscus. Both collaterals lie slightly shtup to the lateral axis of the knee joint and are taut when the knee is full extension. This positioning of the ligaments causes a slackness when flexion occurs, allowing medial and lateral rotation to take place.The cruciate ligaments are so named because of their cross-configuration within the joint. The anterior cruciate ligament attaches to the tibia on its anterior-superior surface, crossing through the joint from the medial side to its lateral attachment on the femur. The posterior cruciate ligament attaches on the posterior-superior aspect of the tibia, crossing diagonally and medially to its lateral attachment on the femur. The anterior and posterior cruciates protect against hyperextension and hyperflexion, respectively.The acti ons performed at the knee let in flexion, extension, and medial and lateral rotation.Flexion is the bending of a joint so that the angle between the two bones decreases. The primary muscles that flex the knee are a group collectively known as hamstrings. The hamstrings consist of the biceps femoris, semitendinosus, semimembranosus. The muscles that assist in flexion are the sartorius, gracilis,... ...gLinea aspera on posterior femur, greater trochanter of femur participate kneecap and via patellar tendon to tibial tuberosityActionExtension of kneeNerveFemoralVASTUS INTERMEDIUSOrigAnterior and lateral femoral shaft salt awayPatella and via patellar tendon to tibial tuberosityActionExtension of the kneeNerveFemoralVASTUS MEDIALISOrigLinea aspera on posterior femurInsertPatella and via patellar tendon to tibial tuberosityActionExtension of kneeNerveFemoralTENSOR FASCIA LATAOrigIliac crest (posterior to ASIS)InsertIliotibial tract (which continues to attach to the lateral condyle of th e tibia)Assists extension of kneeNerveSuperior gluteal