Preventing Knee Injury in Female Athletes
Did you know that female athletes who play popular competitive sports, such as soccer, basketball and volleyball, are at up to 8 times greater risk for injury of the anterior cruciate ligament (ACL) of the knee than their male counterparts? Or that, while some of these injuries come about following an external impact, such as a lateral blow to the knee by another player, the majority occur without any contact at all? These statements are both true and disturbing, but there is good news too. With proper conditioning, these injuries are preventable.
Before delving into more details, let’s all get on the same page with some basic information. The ACL is a tough band of tissue that runs from the thigh bone (or femur) to the shin bone (or tibia). It plays an important role in stabilizing the knee joint. When the ACL tears, it’s often the result of a sudden, forceful twist, such as an awkward landing from a jump that torques the knee. Athletes in sports that require quick pivots and jumps have the highest rates of ACL injury.
Following the well-known “pop” and the scream that often follows, the scenario for most of these injured athletes involves reconstructive surgery and a difficult six to nine months of rehabilitation, as well as a pre-disposition to irreversible post traumatic degenerative joint disease in early adulthood. ACL injuries among young female athletes have reached epidemic levels in many countries, which has athletic trainers, coaches, athletes, parents, and administrators concerned. The prevalence of these injuries has also motivated the athletic and sports medicine communities to work on uncovering the mechanisms underlying the increased susceptibility in these athletes and developing preventative measures. Many theories have subsequently been proposed, having found significant variations between female and male hip and knee anatomy, muscular balance around the knee, and movement patterns. Female sex hormones, including estrogen, progesterone and relaxin, are also thought to play a role, as they are known to fluctuate considerably during the menstrual cycle, most extremely at the onset of menses (first 1-2 days). Reportedly, these swings in hormone levels result in increased ligamentous laxity, and subsequent compromise of neuromuscular coordination, due to inconsistent tautness of these passive tissues.
While nothing can easily be done to change anatomical differences, muscular balance and movement patterns are pliable. Awareness is key as well. Some recent results, including those from a Centers for Disease Control commissioned study using an ACL injury prevention regimen called the PEP program (Prevent injury and Enhance Performance) on a season of NCAA women’s soccer players, suggest that balance and neuromuscular control play the central role in knee joint stability. Through the PEP program and others, successful methods that can be learned and practiced have been identified. The result? Protection of the knee joint complex and prevention of ACL injuries. Several high school and college level teams have incorporated such programs, consisting of a series of proprioception/balance, plyometrics, agility and strength training exercises, into their training, and have seen significant decreases in ACL injuries among their athletes.
Further information regarding the PEP training program, including a complete PEP conditioning schedule with descriptions for all activities, can be found at the Santa Monica Orthopaedic and Sports Medicine Foundation website.
References
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