The most important structure for the ligament is the mechanical structure. In order to maintain stability and limit motion ligaments are supposed to support a lot of stress and force. In addition, when contact sports (ex. soccer, football, basketball) are being played, ligaments, specially those in the knee, face extreme forces and stresses which it must support. Ligaments completely fail after 1730 Newtons or with stresses of over 60MPa. Ligaments also have a tendency to fail when movements are opposed to the joints range of motion.