If tendons are overused they often become inflamed and cause the tissue around them to swell. Another common cause is when people fail to do stretching exercises properly before a workout. One of the most common forms of injury in sports like football is of the cruciate ligament. This is the ligament that holds the knee together. The career of England footballer Paul Gascoigne was nearly ended after a severe cruciate ligament injury.
Doctors can reconstruct severe damage by surgery.
Artificial ligaments are now available.