Female athletes, especially those of basketball and soccer, are experiencing more non-contact ACL (Anterior Cruciate Ligament) injuries than their male counterparts, in fact two to three times more. Why? Although many theories have been proposed, professionals still cannot say for sure.
ACL injuries most often occur from twists to the knee beyond its normal range of motion, which usually occurs when cutting, pivoting, or landing from a jump. Manual examinations can diagnose an ACL tear with 90% accuracy, however, to determine if there is any meniscal cartilage damage or other related injuries, a MRI (Magnetic Resonance Imaging) is usually needed.
There have been a variety of intrinsic and extrinsic factors that have been proposed as possible explainations of the number of ACL injuries in women. Because of the level of training elite athletes go through, both male and female, researchers have turned their focus to the anatomical differences of men and women. Some possibilities include the intercondylar notch, pelvis size, hormones and ligament laxity. The size and shape of the intercondylar notch tends to be smaller in women because women generally have smaller builds. The ACL runs through this notch, from the back of the femur to the front of the tibia, and some say can be sheared during certain jumping and cutting maneuvers. The female pelvis is wider than the males causing the knee to bend inward and a wider Q angle. Because of this wider angle more stress is put on the knee, and some researchers say this could be a reason for the ACL injuries. Ligament laxity and hormones go together. It is known that when a women gives birth, her hormones fluctuate which affects some ligaments in the body, making them more relaxed. There are estrogen and progesterone receptors located on the ACL itself. As hormones fluctuate during a menstrual cycle, the ACL may be affected, increasing the chance of injury.
When looking at extrinsic factors, keep in mind that although the training programs for women have improved, it has been mostly at the elite level. On the average, younger athletes are still not getting the coaching or training needed to prepare them for the rigorous collegiate level of competition.
A study done by Laura Huston, a research engineer, and Edward Wojtys, MD, on neuromuscular performance recently published in the American Journal of Sports Medicine found that "female athletes had more knee joint laxity, less lower extremity strength, less endurance, different muscle recruitment order, and slower muscle reaction time than males." Even though females were found to have strong quadriceps, their hamstrings were still weak, causing a muscle imbalance. Other researchers are looking at proprioception and balance in relation to ACL injuries, as well as the biomechanics of landing and jumping and the type of shoes worn in high incident sports. Despite all the research and theories that are out there, almost everyone will agree that the ACL injury rate is a result from a combination of several factors, both intrinsic and extrinsic.
From my own personal experience, I can say that the surgical procedure followed to reconstruct an ACL after a tear is one of the more painful ones. However, the aggressive rehab (which begins immediately after surgery) helps take your mind off the pain and onto a new goal, getting back in the action. This aggressive rehab style has proven very effective and yields excellent results. It is possible for an athlete to return to play in about four months (though some have made it in two) with a rigorous three to four hours a day, seven days a week rehab schedule. Athletes must retrain their neuromuscular system and be able to perform necessary movements instinctively before returning to action
When it comes down to the facts about ACL injuries, there are many questions and very few answers. For now, the suggestion from athletic trainers and team physicians is to integrate exercises that focus on proprioception, balance, strength and biomechanical techniques into the training programs of our female athletes as early as possible in their careers. Athletes, athletic trainers, coaches and team physicians alike are all anxiously awaiting the release of many studies which are presently in progress.