The function of ligament is to join bone to bone, without ligament our joints would have no stability. All joints (this includes the vertebrae in your spine) have ligament, the ligaments of the knee tend to be the most spoken about because they are often traumatised in sport. Knee ligaments sprain and tear when the joint is put in positions under force that it is not naturally designed to move in- sideways and backwards.
Ligament is a tough fibrous tissue that is flat on the outside of the joint beneath the skin such as in the medial knee ligament or cord like when it is stabilizing the inside of the joint as with the anterior cruciate ligament. Whether the ligament is flat or cord-like they are painful when sprained or torn and the joint loses stability. A sudden tearing of ligaments can even produce an audible snapping noise.
Ligaments are slow to heal which is why surgery is performed. Ligaments are strained when joints dislocate too, as happens with the shoulder. After multiple dislocations ligaments weaken which undermines the general stability of the joint which makes re-dislocations more likely. Artificial ligament is used to reinforce shoulders that are prone to dislocation.
When people stretch too far ligaments can be damaged though muscle tearing is more likely to happen first. Ligaments and muscles may be both injured at the same time. Ligament and muscle tearing is unlikely to happen when you are doing regular age appropriate stretching exercises, when tension is gradually applied to any joint during a stretch you will feel it is about to reach an uncomfortable point before damage is caused. So long as your balance is controlled stretching will usually be safe.
If you are recovering from a ligament injury re-introducing the affected joint to stretching exercise must be gradual and preferably under professional supervision atleast to start with, especially after surgery. Specific stretching exercises post-operative tend to be different to the ones illustrated in Self Massage.
Ligament is present in the parts of the joint that are not meant to bend. Using the example of the knee joint you will find ligament on the inside and outside of the joint because knees due to their structure cannot and should not bend sideways. Ligaments are also located on the back of the knee because knees cannot and should not bend backwards.
You will commonly see footballers with strapped knees, the strapping helps compensate weakened and damaged knee ligaments. Due to the nature of competative sport even with strapping your knees will heal more slowly and re-injure more easily until healing occurs. Unfortunately many sporting careers prematurely end when ligaments become damaged beyond full repair.
Strapping of an injured ankle ligaments might get you through an important game at the end of the season but using strapping as an ongoing method of protecting an unstable ankle will only undermine the health of your knee joint long term.
Damaged ligaments in your leg can create lower back pain because of the lop sided effect on your stride, Self Massage of the lower back and hips can help keep the symptoms under control.