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How Your Knee Works

Content provided by: Better Medicine from Healthgrades

A healthy knee bends easily and rotates slightly. The joint absorbs stress and moves smoothly. This allows you to walk, squat, and turn without pain.

Front view of knee joint showing thigh muscle and tendon attached to kneecap (patella). End of thighbone (femur) and top of shinbone (tibia) are lined and cushioned with articular cartilage. Meniscal cartilage on top of tibia absorbs shock in knee joint. Lateral collateral ligament (LCL) holds thighbone to shinbone on outside side of knee. Medial collateral ligament (MCL) holds thighbone to shinbone on inside side of knee. Patellar ligament connects kneecap to front of shinbone. Cruciate ligaments hold bottom of thighbone to top of shinbone.

A Healthy Knee

The knee is a hinge joint, formed where the thighbone (femur) and the shinbone (tibia) meet. The joint is covered with smooth tissue and powered by large muscles. When all the parts listed below are healthy, a knee should move easily.

  • Cartilage is a layer of smooth tissue. It covers the ends of the thighbone and shinbone. It also lines the back side of the kneecap. Healthy cartilage absorbs stress and allows the knee to bend easily.

  • Muscles power the knee and leg for movement.

  • Tendons attach the muscles to the bones.

  • Ligaments are bands of tissue that connect bones and brace the joint.

Related Video: Osteoarthritis of the Knee

See how osteoarthritis develops when cartilage in the knee tears or erodes and the bones begin to rub together.

Copyright: © 2000-2011 Krames StayWell, 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Reference: Arthritis section on Better Medicine

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