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:
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.
Perhaps one of the most researched topics is ACL injuries. I have been studying and working for years in my clinical practice to find the best ways to rehab athletes following injury as well as implement the most effective injury prevention strategies. Prior studies indicate prevention programs even when self directed can be successful.
However, on the whole injury rates have not declined over the past decade or so. Much attention has been given to valgus landing mechanics, poor muscle firing, stiff landings, genetic difference between males and females, ligament dominance, quad dominance, and so forth. The predominant thoughts today for prevention center around neuromuscular training and eliminating faulty movement patterns (refer to work being done by Timothy Hewett and Darin Padua).
We also know from a biomechanical standpoint that the hamstrings play an integral role in preventing excess anterior tibial translation, and as such hamstring strengthening needs to be a big part of the rehab and prevention program. I believe in hamstring training that allows for activation in non-weaightbearing and weight bearing positions. Common exercises I will use include:
Note: click on any of the thumbnail images above for a full view of the exercise. From left to right: Nordic HS curls, sliding hamstring curls and single leg RDL).
A recent blog post entry by the UNC Department of Exercise and Sport Science (@UNCEXSS) has spurred my post today. Click here to read their entry on optimizing injury prevention based on work done by Professor Troy Blackburn regarding the effect of isometric and isotonic training on hamstring stiffness and ACL loading mechanisms. The research that was done holds promise for hamstring training designed to increased musculotendinous stiffness (MTS).
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:
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:
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.
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:
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:
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.
ACL injuries continue to proliferate among female athletes. I am passionate about preventing them, and part of my professional mission is to study and evolve in my rehab and prevention training approaches all the time to stay on top. I wanted to pass along some new information on a new screening tool just unveiled in the Strength and Conditioning Journal this month.
Before I reveal the screening and training tool, I want to take a moment and review what Timothy Hewett refers to as modifiable risk factors that contribute to injury risk based on his work:
Previously, Hewett has identified that high knee abduction moments are related to high LOAD on the knee and a major risk factor for ACL injury. He and his colleagues have done extensive motion analysis in their lab in Cincinnati, OH. As such, a drop landing test has been used as one tool to observe landing mechanics and assign some risk value to athletes competing in cutting and jumping sports.
In the current article (click here for the abstract) Meyer, Brent, Ford and Hewett unveil a new screening tool involving the tuck jump. They propose that this tool is easier for the S & C coaches to do on the field and not only assess risk factors by way of observing technical flaws, but also use the tool as a training maneuver.
The idea is the subject will perform tuck jumps for 10 seconds consecutively while the observer makes notes on the following pre, mid and post jumping:
Factors 1-3 refer to knee and thigh motion, 4-7 refer to foot position during landing and 8-10 refer to plyometric technique. Coaches are instructed to grade the flaws if seen with check marks during the phases they are seen and use this as a guide for correction. They may also use cameras in the frontal and sagittal plane to assist them.
My thoughts on this are:
In the end, we still lack many answers. According to data published in the Journal of Athletic Training in 2006, non targeted neuromuscular training programs need to be applied to 89 female athletes to prevent 1 ACL tear. So, we need to keep studying and applying science to our training, all the while critically questioning science and looking at our athletes holistically to find the best prevention strategies for each one individually and for at risk athletes as a whole.
In my last post, I shared some practical plyometric drills with you to help teach proper landing mechanics in an effort to reduce ACL injuries. Yesterday, I presented my comprehensive approach to knee training at our ACL Symposium in Cary, NC.
One of the fundamental errors I see coaches and athletes make is abandoning their pre-season training efforts during the in-season. While athletes need to spend the majority of the in-season focusing on sports skills, they must also maintain the neuromuscular training adaptations acquired in the off-season and pre-season.
In my mind, the phrase “use it or lose it” is applicable for the neuromuscular training effects we see with balance, strength, agility and plyometric training. This is especially true for our high risk female athletes like soccer and basketball players who suffer knee sprains, ACL tears and patellofemoral pain at disproportionate rates.
I often hear coaches say, ” I don’t have time to get workouts done and still accomplish what needs to be done at practice.” While, time management may be difficult, I think coaches could probably squeeze in a single training session lasting 15-20 minutes if they simply knew how important it was to the overall health and performance capacity of their team.
With that said, I like to offer simple, yet effective exercises that can be done on a court or field with the whole team simultaneously without the need for expensive equipment. Exercises should focus on activating the glutes (including the medius and minimus) as well as training the hamstrings more since most female athletes tend to be quad dominant.
These exercises are just as effective for males too. So, in the video below I will reveal some exercises I prefer to do to increase strength and reduce injury risk. Perform 2-3 sets of 8-15 reps focusing on strict form throughout.