If you’ve been training and competing for more than a couple of years, you likely know of a few people who’ve torn their anterior cruciate ligament (ACL). This ligament, which connects the femur to the tibia and runs down the outside of the knee, seems particularly vulnerable in women.
According to NCAA data reported in the International Journal of Sports Physical Therapy, female athletes are three times more likely to suffer an ACL tear than their male counterparts. But why is this? And what can be done to minimize your risk? These are the two questions we’ll seek to answer in this article.
Anatomical Differences
Dr. Richard Cunningham is a board-certified orthopedic surgeon and US Ski & Snowboard Team Physician based in Vail, Colorado. In a blog post on his website, he noted that “The incidence of ACL tears is two to eight times greater in female athletes compared to male athletes.” He stated that the alignment of bones, anatomy of soft tissues, muscle imbalances, and overtraining are all contributing factors to women’s risk of ACL injuries.
Cunningham stated “Higher testosterone levels allow for muscle growth. Female athletes have less testosterone. Female athletes also have on average a smaller ACL. Having less muscle per pound of body weight leads to a higher rate of ACL tears.”
An article in the Journal of Orthopedics dug deeper into the potential reasons why women suffer more ACL injuries than men. It began with a bit of myth-busting, stating “Authors frequently state that the female has a wider pelvis than the male. However, females have a narrower pelvis.” That being said, anatomical differences between the two sexes might contribute to females’ ACLs being more prone to getting hurt. These include the size and orientation of the femoral notch (where the ACL inserts) and thinner ligament volume.
The author also reported that women tested in one study had less muscular strength and endurance than the men evaluated, and that “female athletes take significantly longer to generate maximum hamstring torque during isokinetic testing than males.” This might contribute to the muscular imbalance between the front and back of the thigh that Cunningham commented on in his article.
Hormones and Menstrual Cycles
Thanks to research led by exercise scientists like Dr. Stacy Sims, we’re starting to learn more about the impact of hormonal fluctuations during each stage of the menstrual cycle. A study of injury among female soccer players on eight England national teams assessed how this might impact ACL injuries. The authors concluded that “incidence rates (per 1,000-person days) were 47 and 32% greater in the late follicular phase compared with follicular and luteal phases.”
This isn’t to suggest that female athletes should abstain from training or competing when they’re in these phases, as this is often impossible. Whether you’re a weekend warrior or a serious competitor, sporting events and races are held on dates outside of your control. Rather, Dr. Emma Jane Lunan from the University of Glasgow suggests that “monitoring athlete menstrual cycles may be useful to identify points within the cycle that athletes are at increased risk of injuries.”
Strength Training Can Reduce Your Risk of ACL Tears
Another factor for ACL injuries is that many athletes aren’t exposing it and other connective tissues to sufficient load.
“Runners and other endurance athletes might think that they’re strengthening their ligaments, tendons, and bones enough by just doing their sport, but that’s not the case,” said Tim DiFrancesco, DPT, former LA Lakers strength coach and founder of TD Athlete’s Edge. “We can improve the quality and durability of these tissues through consistent strength training.”
The fact that all too many athletes don’t do enough in this area motivated DiFrancesco and Jason Fitzgerald, a USATF-certified running coach, to team up and create the Run Strong program.
“The goal of any strength plan should be to expose the body to loads that prepare them to meet the demands that training and competing will impose,” DiFrancesco said. “We often do all our training front-to-back or up and down, neglecting side-to-side motion. The trouble with this is that when your body is forced to move sideways and you add speed and power into the equation, you can stress the ACL and other connective tissues in ways they’re not prepared for, and injury can occur.”
There is plenty of empirical evidence to prove DiFrancesco’s points. A review published in the Journal of Orthopedic Research examined the efficacy of various interventions that have the potential to mitigate ACL injury risk. They stated that “neuromuscular training programs that target improvements in strength, power, and coordination appear to reduce the risk of ACL injury… Neuromuscular training potentially reduces ACL injury risk by approximately 50% and enhances athletic performance measures in females.”
Exercises That Reduce ACL Tear Risk
DiFrancesco put together a list of exercises that any endurance athlete can incorporate into their existing strength training platform. The following exercises strengthen the muscles surrounding the ACL, reducing your risk of potential injuries:
1. Wall Stork
2. Hands-Supported Kneeler
3. Tempo DB Goblet Spanish Squat
4. Offset Lateral RDL
5. Drop Squat
6. Drop Squat to One-Leg Stick
Consider these exercises as an investment in your long-term health. Just a few minutes a couple of times a week can play a big role in preventing injuries, allowing you to continue training and living an active lifestyle.
References
Cunningham, R. (2022, July 27). Why Muscle Imbalances in Female Athletes Lead to ACL Tears. Retrieved from https://theacldoctor.com/why-muscle-imbalances-in-female-athletes-lead-to-acl-tears-vail-denver-frisco-co/
Hewert, T., et al. (2016, November). Mechanisms, prediction, and prevention of ACL injuries: Cut risk with three sharpened and validated tools. Retrieved from https://pubmed.ncbi.nlm.nih.gov/27612195/
Lunen, E. (2021, April 5). Does injury incidence really change across the menstrual cycle? Highlighting a recent key study. Retrieved from https://blogs.bmj.com/bjsm/2021/04/05/does-injury-incidence-really-change-across-the-menstrual-cycle-highlighting-a-recent-key-study/
Martin, D., et al. (2021, March). Injury Incidence Across the Menstrual Cycle in International Footballers. Retrieved from https://pubmed.ncbi.nlm.nih.gov/33733235/
Orthop, J. (2016, March 24). The female ACL: Why is it more prone to injury? Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4805849/
Silvers-Granelli, H. (2021). Why Female Athletes Injure Their ACL’s More Frequently? What can we do to mitigate their risk? Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8329328/
