**Let me preface this entry by saying that while this is mainly about females and ACL injury risk, I frequently see males demonstrate the same movement patterns that can lead to ACL injury, and males who play multi-directional sports should also be screened for risk factors.**
We got a glimpse of spring earlier this week with temps going above 50 degrees before we got hit with more than a foot of snow at our house last night and this morning. As spring approaches (hopefully soon) millions of kids will be taking to the soccer and lacrosse pitches, tennis courts and softball / baseball fields nationwide. With any sport, there is a risk of injury and this is especially true for female athletes and their risk of “non-contact” ACL injury. In fact, female athletes are at an increased risk of suffering an ACL injury when compared to male athletes in the same sport. Statistics vary depending on the study, but the rates are 2-10 times higher in female athletes!
So why are female athletes more prone to suffering ACL injury?
There are roughly 250,000 ACL tears each year in the United States and women are suffering them much more frequently than men. Part of the reason is that since Title IX was enacted female participation in high school sports has increased 10-fold and collegiate participation 5-fold. With the raw number of female athletes increasing, the number of ACL injuries has increased as well. I’m by no means saying that women should be at home cleaning and learning to cook instead of lacing up their cleats, but women DO need to address some important factors that predispose them to ACL injury.
There are several reasons for this phenomenon and I’ll try to explain them as plainly as possible.
1) Ligament dominance – An imbalance between the neuromuscular and ligament control of dynamic knee stability (relying heavily on the knee ligaments to control stability of the knee) (1)
2) Quad dominance – imbalance between quadriceps strength and hamstring strength, recruitment, and coordination (1)
3) Leg dominance – an imbalance between the two lower extremities in strength, coordination, and control (1)
4) Core dysfunction dominance – an imbalance between the inertial demands of the trunk and core control and coordination to resist it (lack of core control which can affect lower extremity alignment) (2)
5) Posture and alignment – One of the factors I battle on a daily basis at the gym is correcting bad posture. Whether it’s rounded shoulders, forward head posture, extreme lumbar extension, etc., our bones (ligaments) and muscles (tendons) dictate how we move. If there are restrictions in certain areas, the body will compensate with bad movement – which leads to overuse and injury.
As a side note, rapid growth associated with puberty can affect coordination, balance, strength, and neuromuscular control which also come in to play with the above factors. There are some other factors like Q-Angle and ovulation during the menstrual cycle which have shown a relationship to ligament knee injury as well. Many of these factors coexist which further multiplies the risk for injury.

Collateral damage from ACL Injury
In addition to the injury itself, there are many other things to consider when talking about ACL injuries. First, the average cost of an ACL reconstruction is roughly $25,000; not to mention pre-surgery consultations, rehabilitation and medication. Second are the emotional and physical problems. People who suffer ACL injuries tend to gain weight following the injury due to an abrupt decrease in their physical activity. Occasionally athletes can become depressed because their chance of playing college or professional sports may have been affected, which can negatively impact their academic performance. Additionally, those who suffer an ACL injury are at a 50%-100% higher risk to develop knee osteoarthritis later in life.
So with all the associated problems stemming from an ACL injury one would think that we have this trend under control, but we don’t. In fact it’s getting worse. What is interesting is that the frequency of ACL injury is increasing in 10-12 year olds! Why are girls so young tearing their ACL? Unfortunately, many parents and coaches are contributing unknowingly to this trend by encouraging their kids to specialize in one sport at a very young age in hopes that they’ll receive scholarships or maybe even play professionally. This “early specialization” is associated with increased injury risk, shorter athletic careers, and sport “burn out”. Studies actually show that kids who specialize early on have a decreased chance of playing college or professional athletics. A trend I’m particularly frustrated with is that kids today are less physically prepared for athletics. They might be great at soccer or baseball, but they are lousy athletes. THERE IS A DIFFERENCE. Kids spend too much time sitting at home and at school which has altered them physiologically and they only know how to play one sport which limits their exposure to movements and activities outside their single sport.
Additionally, some coaches or trainers have their athletes perform drills that are too advanced for their developed skill set which results in poor performance and sloppy technique. If they learn it incorrectly at this stage, it’s much more difficult to correct it years later! Females also add a disproportionate amount of muscle mass to body mass throughout puberty further reducing their strength and coordination. Subsequently, these advanced exercises become even more dangerous because they haven’t “grown in to their bodies yet.” Lastly, many coaches choose exercises which are downright dangerous but the parents and kids think they’re doing something good because they’re “sore” or “exhausted” after their workout. SORENESS AND EXHAUSTION DO NOT EQUAL QUALITY and college and professional training programs SHOULD NOT BE APPLIED to kids!
Unfortunately, females have the deck stacked against them in terms of risk for non-contact ACL injuries. However with smart exercise programming, attention to detail, and some effort, these risk factors can be mitigated while improving their overall strenght and athletcism.
How do you know if your daughter is at risk for an ACL injury? How can you help her reduce her risk?
The first thing to do is to have your daughter screened for risk factors. During the screening, we are able to identify possible factors and provide a game plan to reduce the risk. This may mean some basic exercises for pre-game and pre-practice warm-ups or a more advanced and thorough hands-on training program. (We recommend each athlete follow a year-round strength and conditioning program with us so we can work closely with them in order to produce a healthier athlete.) Finally, re-test weeks and months later to determine efficacy. EVERY strength and conditioning program we write is based on keeping (or getting) the athlete healthy while improving their strength, coordination, deceleration, acceleration, agility, (AKA athleticism). Certainly some females are more prone to injury and require an increased focus on correcting their imbalances before advancing, but every program is designed to address these numerous factors.
I am hosting an upcoming seminar for female (and male) athletes that will include:
-ACL Risk Screening
-Education for parents, coaches, and athletes
-Corrective exercises to implement on a daily basis to reduce injury risk
If you are interested in learning more about our sport performance training or would like to get details about the seminar, please email me at drew@drfitnessystems.com.
For details about the clinic click here.
If you would like to sign up for the clinic, click here.
Don’t wait until after an ACL tear to find out about ACL injury prevention!
1.Myer GD, Ford KR, and Hewett TE. Rationale and clinical techniques for anterior cruciate ligament injury prevention among female athletes. J Athletic Train 39: 352-364, 2004
2.Myer GD, Chu DA, Brent JL and Hewett TE. Trunk and hip control neuromuscular training for the prevention of knee joint injury. Clin Sports Med 27: 425-448, ix, 2008
As a side note, rapid growth associated with puberty can affect coordination, balance, strength, and neuromuscular control which also come in to play with the above factors. There are some other factors like Q-Angle and ovulation during the menstrual cycle which have shown a relationship to knee injury as well. Many of these factors coexist which multiplies the risk f, and the risk for injury is multiplied.