Monday, October 30, 2017

How Do We Know When Is The Time To Return To Sport? - Part II

Last week we started to look at the research for when is the right time to return to sport.  Is there a time frame or things we should be assessing that the research can provide us some guidance on.  

Currently, the majority of these decisions are based on the most current and up to date information we have available.  Or is it?  Considering that most use a Biodex to make this decision, does an open kinetic chain strength test (Biodex) really tell us anything about how stable the limb is in closed kinetic chain conditions, in running, landing or cutting situations?  Adduction in the frontal plane is a risk factor and hip strength plays a big role in.  Does this test give an indication of hip strength?  Is there a better way to assess frontal plane motion?

Considering the following scenario.  Athlete who is testing for return to play and is tested on a Biodex.  She tests to be within 90% of the non-involved limb.  But this poses several questions.  90% of what.  Is that 90% of good strength which adds to good quality movement or is that 90% of poor strength and quality of movement?  Secondly, does this open kinetic chain test truly reflect closed kinetic chain function.  I think once we see this, we can all clearly see she is at risk, but how do we quantify that?

This is a perfect example and the reason all this is so important is due to the number of athletes that return to play too early and end up being re-injured.  We know from Rugg et al, Am J Sports Med 2014 that players with a previous ACL injury are at an 8 fold increased risk of re-injury, will consume more time on the DL and cost more in health care dollars.  Return too early and you increase injury risk.  Return too early and performance is negatively impacted.  We can all think of a NFL or NBA player who has had an ACLR and once they returned to play, just did not play at the same level as previous or hesitated to move to the injured side.  We can all think of a UFC fighter that was hesitant to move to the previously injured side upon return to the ring.  That hesitation, that lack of confidence has a huge performance impact.

Over the last couple of years, several papers have attempted to look at just that.  In some of our previous blogs we cited   McCullough et al who published a MOON study in 2012 that looked at return to sport following ACL reconstruction.  What they showed was that 63% of high school players and 69% of college players were able to return to sport following ACL reconstruction.  They also showed that only 43% of those athletes were able to return to the same level of sport as prior.  In this case, return to same level of sport was defined as same level of pre-injury performance as self-reported by the athlete.  Similar studies have attempted to do this in NBA players.  Harris et al published a paper in 2013 that looked at the impact of ACLR on future performance in fifty-eight NBA players.  Performance was measured by comparing pre-injury data to post injury data in the following areas: games per season played, minutes played, points & rebounds per game and field goal percentage.  Several interesting findings came out of this study including 40% of the players who tore their ACL during a game, did so in the fourth quarter.  86% of players returned to the NBA and 12% of players returned to the FIBA or D-league.  98% of the players that returned to the NBA and 3% had revision of their ACL.  Performance upon return to sport following surgery declined significantly for all subjects.  However, this was not statistically significant when compared to controls during this same time period.  Busfield et al 2009 also investigated this in NBA players.  They looked at 27 NBA players who had ACLRs.  Of those, 22% did not return to the NBA and 78% did return to play.  Of the 78%, 15% had an increase from pre-injury performance and 44% had a significant reduction from pre-injury performance.
In both of these studies, return to play was determined by performance measures in the game (points, rebounds, free throws, etc).  All of these are good measures of performance but are indirect measures of power output, sprint speed and agility.  Is there a more direct way to measure this impact?  In a June 2014 paper for the American Journal of SportsMedicine, Aune et al looked at return to play in NFL players after a lateral meniscectomy.  In this study, return to play was defined as the ability to play in a regular season game.  Of the 77 subjects, 61% were able to return to play.  Additional findings included only 24.6% of the 77 subjects where still playing in the NFL at follow up (average 4.5 years) and speed position players (running backs, linebackers, etc) were 4.0 times less likely to return to play. 
All these studies bring out some key facts. 

  • Performance is negatively impacted by injuries and with return to sport.  This highlights the importance of directly measuring the pre/post performance variance. 
  • The fact that over 40% tore their ACL in the fourth quarter tells us that fatigue plays a significant role.  This highlights the importance of considering this in the assessment with return to play.    
  • The fact that speed position players were 4.0 times less likely to return to play may indicate the impact that injury has on power output.  Since these positions are so dependent on explosive power and agility, you would expect that if injury does have a big impact on performance that these positions would be the most significantly impacted.
The research is clearly telling us that injury does have an impact on performance.  As such, should we include this as a part of our assessment in return to sport and if we do, how do we do it?  Some will tell you the answer is clear and they are currently doing.  But do we have a standardized return to sport protocol?  No!  Whether it is an agility test, single leg hop test or figure eight, these tests are still very subjective and athletes will often figure out how to compensate to obtain desirable results.  Is there a way to assess an athlete for return to sport that also assesses biomechanical symmetry and performance symmetry?  Yes!  Make sure to check out part III next week we will discuss that in more detail.  For more information on this topic and more, make sure to follow us on twitter @ACL_Prevention or on Instagram @bjjpt_acl_guy

Dr. Nessler is a practicing physical therapist with over 20 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >5000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training.   He is also a competitive athlete in Jiu Jitsu. 

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