Brian Schiff’s Blog
Injury Prevention, Sports Rehab & Performance Training Expert
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Why is it that athletes performing a movement they have done so many times suddenly tear their ACL? We have been studying ACL injury and prevention for many years now, and despite our best efforts, we have not made marked progress in preventing the number of ACL injuries. In addition to anatomical variants and perhaps some genetic predisposition, I feel that the earlier push for sports specialization in our society resulting in increased training/competition hours is a major factor.
The term ACL fatigue may or may not be familiar to you. But in essence, this theory would suggest that after a certain number of impacts/loading, the ACL becomes weakened and less resistant to strain. You could almost compare this to a pitcher who suffers an injury to his medial collateral ligament with too much throwing.
As someone who is consistently rehabbing athletes with ACL tears and screening athletes to assess injury risk, I am always interested in how we can keep people from suffering such a devastating non-contact injury. A recent article in the American Journal of Sports Medicine sought so assess ACL fatigue failure in relation to limited hip internal rotation with repeated pivot landings.
We already know that hip mobility is often an issue for our athletes. Researchers at the University of Michigan sought to determine the effect of limited range of femoral internal rotation, sex, femoral-ACL attachment angle, and tibial eminence volume on in vitro ACL fatigue life during repetitive simulated single leg pivot landings.
Every month there are new papers on ACL surgery and rehab appearing in the literature. I do my best to stay up on them as this is one area of my practice I am extremely passionate about. I am driven to understand as much as I can about both prevention and rehab, but find myself increasingly focused on preventing secondary ACL tears in my patients.
I feel poor movement patterns, muscle imbalances and inefficient neuromuscular control are major risk factors for athletes suffering a primary ACL tear. We also know being female markedly increases injury risk. Research also tells us that males are more likely to suffer a re-tear of the same side, whereas females are more likely to suffer a contralateral injury.
A study just published in the July issue of the American Journal of Sports Medicine looked at the incidence of second ACL injuries 2 years after a primary ACL reconstruction and return to sport. In a nutshell, the findings were:
- 24 months after ACLR and return to sport, patients are at greater risk (6x) to suffer a subsequent ACL tear compared to young athletes w/o a history of ACL injury
- Female athletes in the ACLR group are 5x more likely to suffer a second injury
- The contralateral limb of female athletes is at greatest risk
Click here to read the full abstract
This information is not surprising as I have seen it firsthand in 17 years as a physical therapist. What we do not have much information about is how do the younger patients (e.g 15 and under) really recover from this injury. When should they be cleared? I worked with a young female soccer athlete who tore her ACL and medial meniscus at age 13. She worked diligently with me in rehab 3x/week for about 6 months and then continued training with me at least 2x/week until she was about 1 year out from surgery.
I just finished presenting at our our second ACL Symposium of the year at the Athletic Performance Center last Saturday. Rehabbing and training female athletes has been a passion of mine for some time. Over the years, I have also developed a love for research and reading it, particularly studies on the ACL.
In my practice, I have incorporated jump landing, single leg training and deceleration based training for some time. While we all know females are 3-8 times more likely to suffer an ACL injury than males, we have not isolated the exact reason why. Researchers have offered some clues such as: wider pelvis, narrow femoral notch, smaller ACL, ligament dominance, limb dominance, natural laxity (hormonal factors), wider Q angles, and faulty muscle firing patterns to name a few.
Many of the structural factors are beyond our control. So, as practitioners, we must focus on the training. Consider the following study just published in the August 2011 edition of the American Journal of Sports Medicine that basically reveals females develop peak valgus moments during deceleration during a drop landing maneuver, whereas males develop peak valgus forces during acceleration on the way back up:
Drop Landing
This article adds more evidence that females recruit and fire their muscles very differently than males. More importantly, it reiterates that we as coaches, therapists and S & C professionals need to be working on deceleration mechanics. I believe this starts with simple soft two legged drills such as:
- Small squat jump and holds
- Box drops and holds
- Forward line jump, stick and hold
- Lateral line jump, stick and hold
- 90 degree jump turn, stick and hold
In addition, one of my favorite drills is a single leg forward leap (hop) and stick working on deceleration. The athlete stands on the right leg and then pushes off forward landing on the left leg. Coaching the athlete to land softly on a bent hip and knee while avoiding valgus is important. I usually perform 2-3 sets of 5 reps on each side. Cueing with a mirror, auditory corrections and tactile cues are useful in encouraging proper form.
SL Stick (start)
SL Stick (finish)
It is important to keep in mind that the majority of non-contact ACL tears occur between 0 and 30 degrees of knee flexion. They also typically involve deceleration (landing, jump stop or change of direction), planting or cutting. For this reason, deceleration training must also involve programming for agility and change of direction.
On Saturday, I led the break-out session on deceleration training and covered a few key exercises I use with my athletes. These drills are layered on one another and the basic ones I begin with are:
- Stops – I have athletes accelerate out and then decelerate to a controlled two legged stop after 10-20 yards. Keep in mind allowing for a longer run will allow the athlete to gradually slow down, while decreasing the distance increases intensity and force on the knees. I coach breaking down with small “pitter patter” steps versus a sudden hard stop.
- 2 cone lateral shuffle stops – the athlete shuffles over 5-6 yards and then stops with good hip, knee and foot alignment working to keep the shoulders inside the knees (inside the box). I progress to multiple cone shuffles to increase intensity and maximize repetitive deceleration.
- Pro-agility drills – 3 cones are placed 5 yards apart and I combine linear and lateral movements between the cones layering #1 and #2 above in a continuous pattern to work on acceleration/deceleration combos and change of direction
- Y drill (4 cones) – the athlete runs forward to a cone 5-15 yards out and then performs a 45 degree cut left/right. The progression begins with directed and predictable movement and then advances to reactive cueing with auditory and visual cues.
- Arrow drill (4 cones) – The athlete runs 5-15 yards forward and then performs a 135 degree cut left/right and runs past the cone that serves as the bottom edge of the arrow head. This is much more demanding on the body (knee) and as such I only move to this after the Y drill has been mastered. In addition, I teach a hip turn (from Lee Taft) to reposition the hips and minimize torsion on the lower leg. I move from predictive to reactive agility as in the Y drill.
These exercises are a small sampling of my ACL prehab/rehab routine. I also include an enormous amount of single leg PRE’s and balance training as well. I believe the most important things we can currently do to reduce ACL risk in this population are:
- Screen our athletes to help identify risk (FMS, drop landing, dynamic strength,running/cutting analysis)
- Emphasize hamstring, gluteus medius and lateral rotator strengthening
- Teach landing mechanics and proper deceleration through neuromuscular exercise, biofeedback and repetitive cueing
- Refine proper cutting technique by teaching ideal angles and how to reposition the hips
- Empower coaches and athletes with simple yet effective body weight training routines that can be replicated on the field or court with the team
For now, the battle rages on. I hope you will join me in the quest to prevent these catastrophic injuries. I think as research evolves we will continue to see that the answer to promoting optimal stability at the knee will increasingly have more to do with addressing the hip and ankle. For now, we need to teach soft bent knee landing/cutting that shifts the body’s center of mass forward, while eliminating valgus loading as much as possible in the danger zone.
Whenever I speak at fitness industry events, I always tell my fellow fitness comrades that they must do everything in their power to elevate the profession. I live in both the “rehab” and “training” world daily. I can tell you unequivocally that the words “personal trainer” do not garner tons of respect in the medical community in many cases.
I will share a personal story from my professional work experience this week that illustrates why. Yesterday, I evaluated a new patient (45 y/o male) who just underwent an ACL allograft reconstruction and medial meniscectomy for a medial meniscus tear. See the image below for an illustration of an ACL tear.
When I asked the patient how his injury occurred he replied, “I tore my ACL doing a plyometric workout with the personal trainer at my work.” Ouch! Naturally I wanted to know more. So, I pressed him for more information – things like:
- What kind of plyometrics
- How many
- Were they at the beginning or end of the session
- How long had you been doing them
Let me tell you that a lot of therapists would not have asked these questions. They would have moved on in the evaluation, dismissing this trainer as an incompetent fitness pro in their mind. The fact of the matter is that bad things do happen at times even when we are doping everything just right so I like to give people the benefit of the doubt in most cases.
However, some of his answers led me to believe this particular trainer needed further education. My client said the entire 30-40 minute workout was plyometrics. He was doing single leg multi-directional hops, but actually tore the ACL during a broad jump. He mentioned he had only done a handful of the workouts before getting injured. The kicker was when I asked him if anyone else in the class had been injured, and he remarked that another man recently tore his Achilles tendon.
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