The ACL and the Q Angle
The Q angle is the angle measuring from the ASIS at the hip to the midpoint of the patella (knee cap) at the knee. The larger the angle, the greater the lateral force on the patella basically meaning the wider your hips are the more force is created at your knee. Most women have a larger Q angle, putting the knees in many more compromised positions increasing the risk of an ACL tear. Typically a normal Q angle in men is about 14 degrees and a normal Q angle in women is about 17 degrees. It doesn’t seem like a 3 degree difference can have that much of an effect but remember these are the normal angles and many athletes will not have normal Q angle measurements. This is another reason why female athletes are increasingly prone to ACL injury during the years of puberty because their hips are widening faster than their muscles can keep up with the changes.
The Q angle is an anatomical feature and women or men with wider Q angles are unable to change this about their bodies but by knowing your Q angle and realizing the risk of ACL injury associated with it there are many ways to incorporate strength training and corrective exercise work to help decrease associated injury risk. By addressing compensations at the foot and hip, greater muscular control can decrease force at the knee joint caused by the Q angle. Typically the VMO or Vastus Medialis Oblique muscle in the quads is weaker on athletes with a larger Q angle. This muscle helps to stabilize and correctly position the patella so with a rehabilitation program incorporating strength gains in this and other muscles in the leg; pain and symptoms resulting from a larger Q angle can be controlled and reduced altering biomechanics in your favor.