Can Serious ACL Injuries in Young Female Athletes Be Prevented?
At Marino’s Body Shop we’ve had the opportunity to work with quite a few high school athletes following their rehabilitation from injury or surgery in their quest to return to sport. As a Strength & Conditioning Coach who has developed Continuing Education programs for medical professionals on this subject I look forward to the responsibility for sending our athletes back faster, more agile, stronger and more resilient than before their injury.
One sports-injury topic that has become somewhat shocking in recent years is the difference in the prevalence of Anterior Cruciate Ligament (ACL) injury between males and females in specific sports. The majority of ACL injuries are the result of non-contact planting, landing, changing direction, etc. In sports such as basketball, volleyball, soccer, field hockey and lacrosse, which require jumping, or cutting maneuvers on a variety of surfaces ACL injury rates for females can be as high as 6x that of males.
ACL injuries get a lot of attention because most tears require surgery, have a long recovery with 6 to 9 months or more of rehabilitation, and they significantly reduce an athlete’s value in the eyes of colleges and professional teams. Why? Because even though athletes with a history of an ACL tear may continue to perform well, the biggest predictor of a future ACL injury is a past ACL injury.
About 6 years ago I developed a comprehensive continuing education module to help Physical Therapists and Fitness Professionals understand the current knowledge on injury risk and to help them develop strengthening programs to prevent ACL injury. The research remains as it is was at the time, inconclusive. Researchers have reported a number of correlations, but do not have a distinct causative factor to explain the differences in injury risk between sexes. The best thing we can do at this point is to evaluate the information and build our preventive programs up in respect of all possible factors that increase risk.
The few likely physical or mechanical reasons for the discrepancy in ACL injuries between males and females include:
1. The difference in the size of the femoral notch. Basically, because of smaller bone structure on average, ligaments are also smaller in females. Reduced size = less strength. Yet, females are being asked to manage the same forces on the knee with less structural stability than males in sport.
2. After puberty there appears to be a disruption in the recruitment patterns when girls land from a jump. Prior to puberty the lower body muscle activation patterns are identical between boys and girls. Post-pubertal, the hamstring muscles in girls, which actually support the knee in a similar manner to the ACL, recruit on a slight delay compared to boys placing more demands on the ACL. Moreover, females tend to land with straight legs and with excessive pronation (i.e. knocked-knees), which inhibits the biomechanical alignments necessary to activate the correct muscles for optimizing stability in the knees.
Strengthening the hamstrings can help to improve knee stability, but it’s not enough to just have strong hamstrings, they also have to re-educate the recruitment pattern and train them to be more reactive. This can be developed by teaching good landing mechanics, especially on single leg and in multiple directions or planes of motion. A number of studies have also compared differences in muscle activation patterns between males and females during cutting maneuvers and jumping on the lower legs, and hip musculature and have shown differences. Unfortunately, as with most research…more research on cause and effect is needed before a conclusion can be made.
3. Overall conditioning is a major factor in ACL injuries for both sexes but is even more of an issue for females b/c of 1 and 2 above. Most of these injuries show up early in the season and late in the game or practice when fatigue sets in. Athletes that are ill-prepared because of a lack of year-round strength and conditioning will be more vulnerable. Moreover, athletes who play the same sport year-round without sufficient opportunity for recuperation or time for the integration of complementary strength and conditioning activities may experience the injury as a consequence of over-training.
You might hear that these injuries could be a result of increased joint laxity in females, or monthly hormone shifts, or even because of increased Quadriceps or Q-Angles, which tend to be more prevalent in females. These have all been somewhat ruled out as increasing ACL injury risk in female athletes. Of course, you might have an outlier or extreme instance that doesn’t fit within the general findings. It also doesn’t mean that these issues don’t increase risk for other types of joint injury like Patellofemoral Pain (i.e. Runners Knee), or Ankle Sprains.
So…the big question becomes: CAN YOU PREVENT ACL INJURIES FROM OCCURRING WITH PROPER TRAINING? The answer is a resounding YES!
There have been a handful of studies showing that a simple specifically structured warm-up protocol done for 15 minutes prior to practice and games can significantly reduce or even eliminate ACL injuries. The “original” mass-marketed ACL-prevention warm-up program is called “Sportsmetrics” and was developed by the Cleveland Clinic’s Sports Medicine Group. It’s basically a series of dynamic warm-up drills that are designed to prepare neurological pathways for athletic activities. Other companies have since developed similarly effective protocols.
In addition, I am aware of at least 1 college strength and conditioning program that boasts having just 4 ACL injuries in 11 years. That statistic is almost unheard of as most college programs produce more than 4 per sport season. What are they doing different to produce these results?
There are a couple “missing links” in the common practice of training females athletes. Here is what I believe is most important:
1. Most programs that female athletes are attracted to involve agility-based or drill-based work. This is mostly because young female athletes often believe that if their heart isn’t pumping for 60 minutes, they’re not drenched in sweat or completely exhausted the workout was a waste. Unfortunately, although this concept is being heavily marketed to them, they don’t need this as much as other qualities (i.e. core strength, total body strength, developing good movement). In large class situations there tends to be more focus on overall effort instead of actually having the athletes learn body awareness and focus on building movement skills. For example, the ability to slow down and change direction shouldn’t be simply done repeatedly. It should be taught and performed slowly until the athlete “get’s it”, then speed can be increased gradually. Everyone develops this skill at a different rate.
2. Although basic body-weight drills (squats, lunges, etc) are helpful in learning mechanics there comes a point at which you have to have a concern for building absolute strength, or the ability to handle a load in a controlled situation similar to what may be experienced during play. Males have historically been trained to lift heavy, with many young athletes developing the ability to squat 2x their bodyweight. There remains a stigma associated with weight lifting that needs to be broken and females need to get strong in the off-season if they want to perform at their potential and prevent injuries. The agility drills, and foot-work, have a place in a training program, but their role is secondary.
3. All of the sports that are associated with increased risk for ACL injury require repeated lateral or vertical movement, change of direction and anaerobic energy production. However, when most girls who are serious come in to us for the first time we find out that their “conditioning” is running 5 miles 3 times a week. In other words, they’re over-training their aerobic energy system while under-training their anaerobic system, which is more valuable to sports outside of cross-country, marathon running, etc. Females need to have more balance in their year-round conditioning programs to more specifically prepare them for the demands of their sport. Although some aerobic training is essential to overall conditioning, one long session of 60 minutes or more per week is typically sufficient. The majority of conditioning workouts should be designed to challenge the movements used in the athlete’s sport with short bursts and recoveries similar to game play.
4. Female athletes need to have a greater concern for optimizing their body composition. Females in general carry 8-10% more body fat than males, because of genetics. The recommended body fat% for female athletes is 14-20%. If body fat is significantly out of this range, you are basically forcing the body to have to produce even more force to speed up, slow down, land and change direction. Outside of energy storage and helping to regulate hormones, excess body fat is just along for the ride. When you consider that an extra 10lbs of fat translates to 50lbs more stress on the knees with every jump landing or cut young athletes will appreciate it when it’s gone. Reducing fat while increasing strength and explosiveness should immediately result in increased speed, vertical jump, and faster change of direction. Unfortunately, poor eating habits in HS-aged athletes are more difficult to break than in adults.
5. Last, there needs to be a focus on productive core training. Most athletes tend to focus too much time on anterior core muscles that resist spinal extension and not enough focus on the lateral core muscles that help stabilize the trunk position along with the hip abductors (i.e. glute medius/maximus). Female athletes need less crunching and more planks, side-planks and anti-side-bending and rotational training exercises.
We hope that this information helps to generate awareness for the need to improve training programs for young female athletes.
If you’re a parent, you should be conscious of what your children are doing in their training programs. Do their coaches and trainers understand risk management and are they integrating activities designed to reduce risk in addition to increasing performance?
If you’re a coach, you should be aware of injury risk related to your sport, and at a minimum be integrating an effective neuromuscular warm-up prior to all practices and games. We are happy to provide information if you need some direction. Drop us a line at email@example.com or call 610-873-1063.
If you’re an athlete, we hope that this will help you understand what you need to do to ensure that you can stay on the field / court. After all, most improvement in performance comes from skill practice and game play. All of your off-field/court activities are doing is giving you a stronger, leaner, more resilient and athletic body that has a greater potential for learning the skills of your sport. Understanding WHY you put in the extra work along with EVERYTHING you can do to become a better athlete is a huge step to achieving your athletic goals.
We have begun enrollment for our Summer Strength & Conditioning Program. If you are interested learning more about our HS Athletic Training program please contact us as firstname.lastname@example.org.
Chris Marino, MS, CSCS
Chris is a Strength & Conditioning Coach with nearly 20 years experience. He has developed and delivered continuing education to physical therapists and fitness professionals around the country on joint injury, rehabilitation and return to activity/sport for the past 13 years.