A ligament is a band of fibrous tissue that connects bone to bone, supporting or strengthening a joint, or preventing it from moving in the wrong direction.  They are a vital part of the structure of our entire skeleton, and are present in every joint. Ligaments do not connect muscles to bone, which is the function of tendons. Ligaments are slightly elastic so that they stretch slightly with the movement of the joint. Athletes perform stretching exercises, which make their joints more supple. People who are “double jointed” have very elastic ligaments which allow their joints to stretch and contort further than normal.

Ligaments also support many internal organs, including the uterus, the bladder, the liver, and the diaphragm and help in shaping and supporting the breasts.

If ligaments are put under prolonged tension, they can actually lengthen, which is one reason why a dislocated joint must be returned to its normal position as quickly as possible, to prevent lasting damage to the ligaments.

Unlike many other structures in the human body, ligaments cannot generally heal themselves. For this reason, for those patients whose damaged joint continues to give way after the injury and who do not respond to conservative treatment such as physiotherapy or a brace, the ligament often has to be reconstructed.

The study of ligaments is called desmology.