The anterior and posterior ligaments connect the femur to the tibia (thigh to lower leg). They are named cruciate because they cross each other like the letter "X" [14] . The two cruciate ligaments work together to stabilize the knee joint and resist extreme ranges of motion [13]. The function of these ligaments is complex. As the knee bends and straightens, the cruciate ligaments twist and change orientation to stabilize the knee. Although there are different bundles for both the anterior and posterior ligaments, most of the bundles of the anterior ligament become taut as the knee extends (straightens). Most of the bundles of the posterior ligament became taut as the knee flexes (bends). There are some bundles of both the anterior and posterior ligaments that remain taut throughout the entire range of motion [14].