Thursday, April 4, 2013

Women's Soccer and ACL Injuries - New Study Leading Way In Performance & Prevention

With soccer season in full swing for most, a lot of people are thinking about one thing.  Is this the season one of my players or my child will have an Anterior Cruciate Ligament (ACL) injury?  Hopefully the answer is no but with participation in athletics comes an inherent risk of athletic injury.  In high school athletics, football has the highest severe injury rate per 1000 (athletic exposures) AEs, followed by wrestling, girls’ basketball and girls’ soccer.  Among comparable sports, females sustain a higher severe injury rate than boys per AE with the knee and ankle accounting for over 41% of the most common severely injured body sites.   Studies show female athletes are 3-8 times more likely to rupture their ACL than their male counterpart per AE. 

Can these be prevented?  If they can be prevented, can that intervention also impact athletic performance?  That is exactly what a team of scientists are attempting to determine in a new study being conducted by the American Sports Medicine Institute and Andrews Sports Medicine in Birmingham, Alabama.  In this study, researchers will be evaluating female D1 and D2 soccer players at 4 different universities in 2 different states over 3-4 years.  2 universities will serve as an intervention group and 2 will serve as a control group.  All the athletes will be screened using the Dynamic Movement Assessment™ or DMA™.  The DMA™ is filmed and analyzed with Dartfish technology.  With Dartfish, researchers can quantify movement and determine each individual’s deficits based on their results.  Each athlete’s vertical jump and 10 yard split time is also recorded in order to determine impact on these performance measures.  Those in the intervention group will have corrective exercises prescribed based on how they present which they will perform throughout the season.  All will be followed throughout the year to determine impact on injury rates and athletic performance.

Along with seeing the impact on performance, researchers also want to determine the impact of fatigue on movement.  Therefore, they will also be performing a fatigue protocol with all the athletes and having them repeat the Dynamic Movement Assessment™.  This will allow them to compare the athletes’ movement patterns pre and post fatigue.  Why look at fatigue?  There is an abundance of research and empirical data that indicates athletes are more susceptible to injury as they fatigue.  It is well known that the rate of non-contact injuries increases with the length of participation (in the later quarters of the game) due to muscular fatigue.  What this will attempt to show is what impact fatigue has on mechanics.  This is being done to determine if done in combination with the DMA™, does this become a more accurate predictor of injury. 

Why look at movement at all?  Over the last decade, there has been a plethora of research that shows strong correlation with “pathokinematics” (abnormal movement patterns) and increased risk for injury in high impact sports.  These pathokinematics present in a predictable pattern and can be assessed with certain movements.  Using the information that is gained from this, the skilled clinician can then develop a corrective exercise program that improves these movements on these tests.  Therefore, improving these movement patterns would theoretically reduce the risk for injury.  And that is exactly what the preliminary data is indicating.  But, can improvement in these patterns also improve performance?
It would make sense that improved efficiency of movement would result in improved athletic performance.  Looking at a single leg squat, it is easy to see how improvement in the mechanics with would result in improved ability to generate greater force with push-off (sprinting or vertical jump).  Hence, this would result in improved sprint speed and increases in vertical jump.  In their previous pilot study, the group found just that with significant improvements in vertical jump and 40 yard dash.  This current study is designed to assess impact on both the vertical jump as well as 10 yard split times and compare that to those without an intervention.  Although the preliminary data is not clear on this point yet, what we do know is that overall team performance has improved.   With keeping the team’s key players off the disabled list, the team’s overall performance has been improved.  If there is a direct impact to individual performance, then this makes these types of injury prevention programs much more attractive to coaches, parents and athletes.  For the impact on injuries is one thing but if you can also drive significant improvement in performance, then this will be much more engaging to those with limited resources and time to do all that is possible for a successful season.

About the author:  Trent Nessler, PT, MPT, DPT is a physical therapist and CEO/Founder of Accelerated Conditioning and Learning (A.C.L.), LLC.  He is the researcher and developer the Dynamic Movement Assessment™, author of the textbook Dynamic Movement Assessment™: Enhance Performance and Prevent Injury, and associate editor for International Journal of Athletic Therapy & Training.


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