Knee joint showing associated ligaments.
A ligament is a short band of tough but flexible connective tissue that, in most cases, holds two or more bones together at a movable joint. Ligaments restrain the movement of bones at a joint and are therefore important in preventing dislocation.
Ligaments are of two types. The majority are composed of collagen fibers and are unstretchable under normal conditions. Examples of this type of ligament are the iliofemoral ligament of the hip joint and the collateral ligaments of the elbow joint. The second type is composed largely of elastic tissue and can therefore regain its original length after stretching. Examples include the ligamentum flavum of the spinal column and the calcaneonavicular ligament of the foot.
Ligaments also support various organs, including the uterus, bladder, liver, and diaphragm, and help maintain the shape of the breasts.
Note: Whereas a ligament joins bone to bone, a tendon joins muscle to bone.