Almost everyone has heard the words anterior cruciate ligament. The ACL is a very important stabilizing cable or ligament connecting the femur to the tibia preventing anterior translation of the tibia beneath the femur.
With excessive rotation, hyperextension, impact, landing from jumps, the strength of this ligament can be exceeded resulting incompetency of his function when significantly stretched, avulsed, or torn.
When the ACL is functioning, this injury changes the stable knee to an anterior lateral rotatory instability which the knee can buckle, shift out of place, give way, collapse, and limit our desired activity level.
An intact ACL is needed in the majority of our activity levels, manuevers, exercises, and sports that generate more stress, shear, pivoting, impact, and torque and the injured non functional ACL must be replaced or reconstruction.