By Carl Valle
Even with all of the research, expert opinions, and screening systems available, athletes are destroying their knees every single day. The reasons are clear and the solutions are simple, but the application of eccentric training is hard to employ. However, this article is not about a system to reduce injuries or a program to rehabilitate ACLs. Screening isn’t even the focus of this article, since we have enough good information to help reduce ACL tears. The purpose of this article is to do a better job with the basics, and that is gross eccentric strength for team sports.
Other factors like foot mechanics, proprioception, and conditioning are important, but they are way beyond the scope of this article. My motivation to write this is the fact that I have never had an athlete tear an ACL under my care. It’s not because I am doing something special; it’s because some great coaches have shared how training solves injury problems, not special exercises.
When I worked at the Longfellow Club with Tim Crowley, a former soccer player, we produced state champions and All-Americans like a factory because of talent and hard work. I was most proud of the fact that we did a great job reducing injuries while at Longfellow because we focused on performance—and weren’t scared to train. What I learned was simple: Reducing injuries is about the quality and duration of preparation, not about giving into what parents and administrators want.In order to reduce injuries, focus on the quality and duration of preparation and training. Click To Tweet
My promise is a bold one: I will identify the outside factors that result in higher ACL injury rates and share what to do to reduce them, based on current research and best practices I have learned from great people.
Why Your Program Is Injury Plagued or a Ticking Time Bomb
Many great coaches don’t get the recognition they deserve because of factors outside their control. I have been a part of state champion teams, as well as teams that struggle to finish the season in one piece. If it weren’t for the fact that injuries are truly ruining the quality of life and dreams of athletes, the current state of sports would be laughable.
Many team coaches fire strength coaches when athletes get injured. Many strength coaches become frustrated with medical professionals limiting themselves only to what they do best. Many medical professionals are tired of dealing with team coaches who don’t prescribe practices based on biology, but just on strategy and time. It’s a vicious cycle, and athletes suffer. Many times they simply show up for the season out of shape, blaming everyone for their problems. Nothing has changed in sports because everyone cares about their job more than they care about the profession as a whole, and the trend looks ominous at best.
A core problem is that, in every sport, the staff suffers from being what I call “departmentalized”—they’re not on the same page. Most programs try to prevent silos from happening with athlete information, but if you are monitoring athletes without having a solid Performance Model, you are just floating and not sailing in the right direction. I have done what many people have done: focusing on being a team player and compromising so much that nobody benefited, especially the athletes. The years I was a head coach in swimming and track and field we set records and won more races. The results were similar during the years that I was an assistant, but injury rates were high and personal best percentages were much lower.
I fought against the overtraining and competing short (with a nagging injury) many times. While the results were less than stellar, I knew if I bumped into the athlete years later they would be glad to see me because they would not be limping around or showing incision scars from surgeries. On the other hand, I have failed athletes a few times because I was afraid to say something—I cared more about job preservation than fighting a lost battle. However, now that I’m a post-college coach, I can say and do what I want, to a point.
When you’re in the private sector, the athlete is the boss, not the head coach or athletic director. This means they pay you and you are servicing them. While on the private side, I’ve learned that avoiding conflict doesn’t work, but transparency, objective criteria, a positive environment, and a little salesmanship do. It takes longer, sometimes even years longer, but outlining what you believe training-wise and making sure everyone is aware of each other’s work does make a difference. Many good programs and good coaches fail, not because of what they do, but because everybody’s actions on the team are not collaborative, just cooperative.
It’s not about blame—it’s about each person being aware of his or her responsibilities and expertise, and then stepping back and seeing the complete, collective performance model. Coaches in performance need to fail better; meaning that they need to make smart mistakes based on their own choices, and then be aware of what went wrong. Most failures I have been involved with have never been repeated, and sometimes that meant making changes to things that I didn’t want to change.Performance coaches need to fail better, making smart mistakes and learning from what went wrong. Click To Tweet
Screening for Preparation vs. Talent Identification (Ability)
Coaches need to know the difference between testing absolute acute ability and evaluating preparation from training. I have seen some great jump and sprint performances from athletes who never trained, and I have also been lucky to work with talented athletes that come in relatively finished. Derek Hansen has used the term “Diamond Polishers,” coined from his colleague (for the record). These are coaches who associate their work with the hyper talents of some athletes, instead of only taking credit for results or changes that are due to their training.
When evaluating readiness to play, it’s not just about acute freshness or ability. It’s about what the athlete has done over the last few months to deserve the right to play. True elite sport is about entertainment schedules for fans (increased risk), but many athletes are not taking advantage of short periods of down time or the resources they have. If you want to reduce injuries, evaluate an athlete’s training and not just their ability. Plenty of resources exist on screening for ACLs with biomechanics, but it’s not about teaching youth soccer landing mechanics or single leg exercises—it’s about simply asking if they made a strength adaptation that can be seen on the field.
Eccentric Strength and ACL Injury Rates
I have nothing against posterior chain exercises, but what I tend to see is a lot of concentric favoritism because the numbers look good early, and athletes don’t complain about delayed onset muscle soreness (DOMS). What happens is the eccentric utilization ratio (EUR) becomes equalized, and injuries rise rapidly. I once spent an entire Sunday morning (three hours) in horror, doing research on programs that are reducing injuries in American youth soccer, and finding nothing of interest. Expanding my research, I went into international studies and saw even more annoying approaches.
There are countless recommendations on body awareness, balance training, and flexibility routines, but none of the meat-and-potatoes, such as real strength training. Most of the studies I saw were led by orthopedists and some PTs—not an ideal population for guiding what training should be. I’ve got nothing against the medical community, but the programs I saw for both adult males and youth populations were things I would do with retirement home residents, not with athletes decelerating on the pitch, like Ronaldo.
The research shows that having a strength component will help, but having your own program versus implementing someone’s effective program is key. Appropriate age- and career-related expectations must be considered. For instance, the ability to do a goblet squat is not sports preparation; goblet squats are an exercise to prepare for training. I am excited that low-level strength can help, but having solid strength training is about having a measureable quality that can be universally compared. We need better strength evaluation that is practical for coaches and can be objectively reviewed by anyone.
The Problem With Bodyweight Strength Training
Sprinting and jumping are essential to training, but bodyweight exercises are too general and unlikely to get effective advancement from most athletes. Single leg exercises and pull-ups are great, but external loading will eventually be needed. Many coaches who are afraid to journey outside coastal waters and just stay comfortable with body weight exercises instead of going explosive or adding heavy external loads are only hurting the athletes. True, amazing results can be seen with depletion and intense options, but after demanding bodyweight exercises are accomplished, we tend to see people drifting to unstable surfaces to find a way to increase difficulty versus contractile strength.
If an athlete is getting hurt with their own body weight in sport, you need to make a strength reserve beyond bodyweight or the law of diminishing returns on endless bodyweight reps will come back to haunt you. Again, bodyweight training and teaching exercises are fine, but without overload, high repetitions become conditioning tools, not strength options.
Deceleration Benchmarks and Bodyweight Multipliers
When we look at most ACL injuries on video, many case studies show the need for the athlete to have eccentric qualities decelerating forces. Even a 160-pound athlete will be exhibiting hundreds of pounds of force when cutting, yet we see YouTube videos that show five-kilo sandbags and stability routines. I made the mistake of being part of the crowd laughing at silly exercises, but now it’s no longer funny, and it’s a problem. The honest standard of strength will be based on the need for handling forces that occur in games that athletes fail to resist. If a program doesn’t address gross forces and hides weakness with everything else tossed in, it’s unethical.
Athletes must have the gross contractile muscular strength to overcome supra-gravity and momentum events.
The above statement sounds fancy, but I wanted to make sure the language was pure and precise. Deceleration injuries to ACLs are strongly tied to eccentric ability, and athletes tend to lose this quality as competition increases and training decreases. Fatigue matters, but fatigue is about accumulation of recovery from an athlete’s maximal ability. If an athlete has a poor maximal ability, they are not likely to have much in reserve for when the season is long. So, instead of thinking of exercises that mimic motions, think about training programs as a whole; reducing risk by increasing adaptations that are known to be effective interventions.
Scoring Strength and Power Training in the Field
In the past, I have shared weight room tests and plyometric exercises, so this is more of looking at comparisons to athlete ability and training. Evaluating a program is much harder to do than evaluating a test, because it’s time dependent. These are the major considerations in evaluating a training program for leg strength and power, and I have no composite score yet because this is more of an open process than a convenient scoring solution. Here are ten major and primary factors to evaluate.
- What are the athlete’s best field tests? When comparing year to year, if you are not doing something maximal or very near maximal, the data is not as valuable.
- How has the baseline changed versus the final test? If an athlete started in amazing shape, when they left were they better because they’d learned to test better or were they physiologically better from being able to adapt to the other needs like conditioning?
- If the athlete came in unprepared, are they expected to compete that way and let the season increase their fitness? If so, does the program have a history of managing this creatively with low injury rates or is it a crap shoot?
- Did the resistance program improve qualities of durability by showing training adaptations? Some absolute ability tests may decrease from fatigue of practices, but are the legs getting stronger? This is the time I like to see Velocity Based Training metrics, since external loading is important for training data. Flanagan and Jovanovic have some great bar velocity equations to evaluate maximal strength. Even if a soccer club isn’t lifting like Westside Barbell, it doesn’t mean that maximal strength can’t be tested.
- Can the athlete express great force qualities with both single leg and double leg exercises? The bilateral deficit is not well understood in the blogosphere, so please look at noted authorities and researchers who understand the need for bilateral facilitation.
- Use the Raptor Test to get the EUR and make sure the repeated jumps don’t lag behind. Compare unloaded jumps to loaded jumps for training changes.
- Most of the VBT sensors do a poor job of addressing limb asymmetry. Don’t trust proprietary scoring units or “in-house algorithms.” Gross strength deficits between right and left legs can be seen with simple field tests.
- Eccentric qualities with tests are often joint angle specific, so make sure you test deeper squatting patterns to see muscular contribution ratios.
- Use kinematic data with the use of video analysis to look at joint control, not just athletes with blessed nervous systems who score well kinetically. Many athletes hide in jump tests even with valgus collapse because what makes them at risk is also something they are able to exploit by cheating with compensation.
- Use physiological and biochemical monitoring to ensure that the athlete didn’t get to the numbers by digging themselves into a hole. Many athletes improve, but are on fumes by the end of a training program and need to be unloaded.
Most coaches will ask, “How do I know my high school JV basketball player is ready to play?” I don’t have an answer, but I do have the questions that lead to the solution. To take a simple step forward, ask yourself how many strength sessions were done, how much improvement the athlete has made over the time period, and if they can handle an X multiplier of load compared to body weight. Gross and bilateral, and even some unilateral, scores can be very pointed. An athlete who is unable to do some sort of squat (front, back, split) with external load has a problem. Sure, eight-year-old kids need PE and don’t need strength testing, but 15-year-old athletes unable to do lunges while still playing club sports year-round is disgusting.
Body Power, External Load Power, and System Power
Coaches need to look at the relationships of current and baseline power metrics and eccentric metrics. Athletes need to make sure balance, often expressed in ratios, is not deviated from too much or injuries will increase. Note: Most technologies look at the concentric or positive work; it’s important to look at all of the negative (eccentric) work in training.
Body Power: Common Speed and Jumping Profiles, including Agility. Linear speed metrics can be compared to lateral qualities. Eccentric and reactive jumps can be compared as well.
Key Training Point: Athletes need to improve or maintain their body power.
External Load Power: Ball and Barbell Indices can be used to see how the athlete pushes their absolute qualities as compared to their relative abilities. Most strength options don’t help identify eccentric qualities, but high maximal loads show training status very well. Keep in mind that force analysis from different instruments is not interchangeable, and sometimes a software update may change the calculations, so be careful.
Key Training Point: Athletes need to improve or maintain their external power if their abilities are higher than their own training scores.
System Power: The sum of total body and external load in exercise is a great way to see the depth of training. The depth of training is how close to their genetic ability the athlete is hitting, based on the length of time they are spending in near-personal-best loading or testing periods.
Key Training Point: Athletes need to spend longer time periods at best training levels in order to have their training transfer to sport and injury prevention. Good system power over time is a product of talent and training.
A good takeaway is not just looking at an athlete’s past peak ability, but how much training time that athlete currently needs to express near-best abilities. When athletes talk about their best training scores as ancient history, and they haven’t happened recently, it’s likely they are a ticking time bomb. The length of the fuse is highly related to the most current near maximal training, and the total number of sessions spent at that level.
Testing Peak Eccentric Forces With Field Tests
I promised that this article would not be a screening system because plenty of good people have excellent ways to evaluate risk with athletes. Three tests I have found useful are: double leg landing options, single leg squatting, and the hop and stop. Why these three? All of them are safe, which means you can get good scoring without pushing the limits. The more aggressive the test, the more likely it is that a problem exists. I don’t like tests that go full blast without observing training and building up slowly. Landing tests and redirection jumps with high velocity counter movement and options like a low box are a safer middle ground.
Single leg strength gives great information and a simple video station can show possible risk factors or poor strength qualities in kinematic motions. Finally, deceleration with rapid and short jump tests is also a good predictor. I am working on making the tests more engaging without resorting to silly games like tag, but this will take a while because the games require wearable sensors. Tape measurements and video analysis are currently good enough.
Most of the information collected is kinematic (motion) versus kinetic (forces), but instead of looking at wattage or other units, think about distance or time. Contact mats are good, but in-shoe pressure is far more revealing. Earlier, I stated that I didn’t want to get into foot mechanics, as that is outside the scope of most people’s knowledge. However, simple data can be teased out and the advanced anatomical and foot mechanic information can be acquired and pushed to coaches and trainers with that type of experience.
Training Peak Eccentric Forces With the kBox
The kBox provides the option to use the kMeter, a device that actually transfers the information from the flywheel drive shaft to mobile devices like an iPad or iPhone. I have already briefly described how flywheel forces work in my post on the Five Resistance Elements that Develop Athletes, so I will get more into what exercises are suggested for ACL and performance resilience and enhancement. Again, exercises are the end recipe to prescribing training, so what I find to be good for other needs like hamstring development also feeds into deceleration and force control with ACL prevention and rehab programs.
No magic exercise exists, but a well-rounded program should help bring about strength that you can use. The four exercises I suggest are:
- Split Squats – This exercise targets the front supported leg with less contribution from the rear foot. Use a bench or similar option to keep the support without having too much contribution outside the main leg.
- Deep Traditional Squats – Deep traditional squats are awesome. The EMG readings are very exciting and I highly suggest making sure the athlete can squat deeply with the assessment of the hip by Dr. McGill. The goal of this movement is to squat the same as you would with barbells with regard to depth and pelvic position.
- Squat and RDL Patterns – Squatting the exercise up and lowering with one leg creates a very obvious risk-to-return ratio. Similar to jumping with two legs and landing with one, the overload comes from having the leg eccentrically control a force that it can’t create concentrically, leading to a planned challenge. RDLs require a lot of steady progression before aggressive loading can be done, and the asymmetrical loading does recruit muscle groups differently than bilateral options.
- Lateral Squats – Similar to split squats but lateral in nature, fresh muscle groups are recruited slightly differently with this exercise. Loading can be more aggressive because the footing is static and positioned without extra technical demand.
Keep in mind that the above exercises are major contributors to the athlete’s strength, but not their only needs. Plyometrics, field technique, conventional options, and general strength options like core and other elements are also necessary.
Getting Started With Flywheel Eccentric Forces
The Flywheel is not a miracle device and will not turn mules into thoroughbreds. The ACL will not regrow like some EMS companies claim and, if you are 65 years old and have not made the NBA yet, it will not make your basketball dreams come true.
The suggestion is to be familiar with the exercises and slowly integrate them in order to reinforce great movement patterns. Make sure athletes know how to do the patterns without external loads and without flywheels. Skipping steps and trying to teach and train at the same time because the kBox is a machine is not worth the risk. Additionally, many flywheel options range in the way that they create forces so each system must be learned slowly. The research on injuries and adaptations is strong enough to have NASA invest in flywheel training. After you’ve read this article, I hope you’ll see the value of the equipment, too.