We Don't Know What We Don't Know....But We Know More Than We Think!

Several years ago, I had the opportunity to meet a gentleman who has had a tremendous influence on me, both from  a clinical aspect but also from the non-clinical aspect.  This individual is not a clinician but a very intellegent individual for whom I have a lot of respect for and who poccesses a lot of intuitive insight.  He is often famous for a phrase that he will often qoute in talks and conversation and that is:

We Don’t Know  What We Don’t Know

Victor Bergonzoli – CEO Dartfish

That qoute has not only stuck with me but has also influenced clinically and drives the way I will look at research and development of what we do.  Two recent experiences at the 2015 NFL Combine and the APTA Combined Sections meeting lead me to believe that there needs to be more innovation in the way we look at return to sport for athletes and the way we approach risk factors.  Currently, this is one of the hottest topics in sports medicine and has been a debatable discussion for over 12 years.  Yet, we still do not have much of a standardized way to make informed decisions on return to sport.  We Don’t Know What We Don’t Know….but we do know a lot that we can use.  Before we begin this discussion, we want to clarify a term we will use in this blog, total risk.  For the purposes of this discussion, we will use the term total risk to mean risk determined by a combination of demographic data, biometric data, movement data and symmetry data.

Just looking at the Febuary 2015 issue of American Journal of Sports Medicine and you will find a plethora of information on what we should be considering in determining risk factors.  Newman et al looked for factors that influence concomitant injuries that occur in those who have an anterior cruciate ligament reconstruction.  Although this was looking at those who already had an ACL injury, the purpose was to see if there are factors that contribute to the prevalence and severity of associated chondral and meniscal injuries.  The authors found that a delay in the time to surgery resulted in greater prevalence of irreparable meniscal injuries and severity of chondral injury (take note of that parents).  It also found that those who returned to play prior to surgery had increased severity of chondral and meniscal injuries.  The authors also found that obesity played a significant influence on both the prevalence and severity of concomitant injuries associated with ACL ruptures.  So in our discussion of looking at risk factors, this brings forth the need to consider BMI (body mass index) of the athlete when attempting to assess total risk.

In 2014 study by Rugg et al, we know that athletes who have had a knee injury or surgery prior to a Division I college athletic career are not only at greater risk of re-injury but that will also spend more time on the injury reserve during their college career.  Andernord et al attempted to further identify predictors of contralateral ACL reconstruction (ACLR) in a 5 year follow up in athletes who had already undergone a primary ipsilateral ACLR.  This was a massive study looking at 9061 subjects from 2005 till 2013.  The authors showed those under the age of 20 were at a much higher risk with males at a 2.4 times higher risk and females at a 2.9 times higher risk of contralateral ACLR.  This study further concluded that females undergoing a ACLR using a autograft from the contralateral limb were 3 times higher risk than those who did not.  So, in our discussion of looking at risk factors, this brings forth the need to consider both previous knee and ACL injury, age and gender of the athlete when attempting to assess total risk.

We know from the work by Quatman et al, that abnormal biomechanical movement patterns increase risk of non- contact lower limb injury.  We also know from a 2013 study by Kristinaslund et al that single limb testing gives a better indication of how the lower limb moves in sport that just bilateral testing.  Pollard et al showed that female soccer players who undergo ACLR have asymmetrical movement patterns during side-stepping cutting maneuvers which contribute to re-injury risk.  So, in our discussion of looking at risk factors, this brings forth the need to consider both abnormal biomechanical movement patterns (the specific movements) as well as do those movements present themselves during single limb testing. 

Recently we were asked to do a guest blog on the psychological aspects that must be considered.  One landmark studies in this area and which greatly influenced us was by Ardern et al in 2013.  Here the authors looked at the psychological responses that influenced return to sport.  In our blog Psychological Responses Matter  In Return To Sport After ACLR, we touched on specific strategies that we as clinicians can do to minimize these negative influences.  In a recent 2015 study by Lentz et al, they looked further at factors that influence return to sport following ACLR.  These authors found some similar findings.  Specifically that an elevated pain related fear of movement or reinjury, quadriceps weakness and lack of confidence lead to increase risk of reinjury and decreased likelihood of return to sport.  Considering these findings, reviewing the previous blog on psychological factors will provide us with tools we can use in the rehabilitation process to aid in reducing these influences.  However, in our discussion of looking at risk factors, this brings forth the need to consider pain level, quadricep strength and lack of confidence.

Considering all the above information, there are multiple factors that must be considered when determining risk of injury in athletics.  Historically, we tend to focus solely on the movement with our assessments.  When in reality, we need to consider the whole athlete.  Their previous orthopedic history, their biometrics, their movement in bilateral and single limb performance as well as their psychological status (confidence).  It would make sense the more of these factors that are considered, the more accurate our injury prediction tools will become. 

Can we change that?  What if the technology was available that included all those?  No matter how good we are at assessing, if we train without implementing the fundamentals of what we do know, then results will be the same.  Next week we will dive into what we do know.  We hope that you found this blog insightful and useful.  Stay tuned for part II of this series.  If you like what you see, SHARE THE PASSION!  It is the biggest compliment you can give.  Follow us on Twitter @ACL_prevention and tweet about it.  #Evolve and help us spread the passion and #3DDMA.

Build Athletes to Perform…Build Athletes to Last!™

Trent Nessler, PT, MPT, DPT:  CEO/Founder ACL, LLC | Author | Innovator in Movement Science and Technology.  Dr. Nessler is a physical therapist and CEO/Founder of ACL, LLC.  He is the researcher and developer the Dynamic Movement Assessment™, Fatigue Dynamic Movement Assessment™, 3D-DMA™, author of the textbook Dynamic Movement Assessment: Enhance Performance and Prevent Injury, and associate editor for International Journal of Athletic Therapy & Training. For more information, please see our website at www.aclprogram.com