Example: Basketball player coming down after a jump shot or the gymnast landing on a dismount. Straight-knee landing - results when the foot strikes the ground with the knee straight.Example: Football or baseball player making a fast cut and changing direction. Planting and cutting - the foot is positioned firmly on the ground followed by the leg (and body for that matter) turning one direction or the other.Often those are non-contact activities with the mechanism of injury usually involving: Pivoting injuries of the knee with excessive inward turning of the lower leg can also damage the ACL.īasically any athletic or non-athletic related activity in which the knee is forced into hyperextension and/or internal rotation may result in an ACL tear.
This position of the knee forces the lower leg excessively forward in relation to the upper leg. Hyperextension of the knee, that is, if the knee is straightened more than 10 degrees beyond its normal fully straightened position, is a very common cause of an torn ACL.The movements of the knee that can result in a tear of the ACL are described as follows: Its usually due to a sudden stop and twisting motion of the knee, or a force or "blow" to the front of the knee It limits rotational movements of the knee.Ī tear of the anterior cruciate ligament (ACL) results from overstretching of this ligament when certain movements of the knee put too great a strain on the ACL.It restrains excessive forward movement of the lower leg bone (the tibia) in relation to the thigh bone (the femur).The function of the ACL is to provide stability to the knee and minimize stress across the knee joint: They connect bone to bone across the joint. Ligaments are strong, dense structures made of connective tissue that stabilize a joint. The 2 ligaments inside the knee joint 'cross' each other. The other is the PCL (posterior cruciate ligament). It is one of 2 strong ligaments inside knee joint. The ACL is short for Anterior Cruciate Ligament.