Joints, particularly hinge joints like the elbow and the knee, are complex structures made up of bone, muscles, synovium and cartilage and ligaments, designed to bear weight and move the body through space. The knee consists of the femur (thigh bone) above, and the tibia (shin bone) and fibula below. The patella, or kneecap rides on top of the lower portion of the femur and the top portion of the tibia. The muscles and ligaments connect these bones and the space between them is cushioned by fluid-filled capsules (synovia) and cartilage. When muscles are exercised, they pull on the bones, strengthening them. The range of motion of a joint represents how far it can be flexed (bent) and extended (stretched).

Review Date:3/9/2007
Reviewed By:Thomas N. Joseph, MD, Private Practice specializing in Orthopaedics, subspecialty Foot and Ankle, Camden Bone & Joint, Camden, SC. Review provided by VeriMed Healthcare Network.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.