Monday, July 17, 2017

How Will Your NFL Team Perform? - Know Their Injury Rates - Part I

Over the course of our last series “Is there a secret sauce” we provided some thoughts and research on several factors that contribute to altered biomechanics or pathokinematics that put athletes at risk for an Anterior Cruciate Ligament (ACL) injury.  Throughout the history of this blog, we have attempted to correlate these same pathokinematics to not only ACL risk but also to changes in athletic and team performance.  In this authors mind, there are two ways in which this impacts performance; directly or indirectly.

The direct impact is the impact that altered biomechanics has to force production and kinetic energy transfer.  This direct impact results in muscles of the core and lower kinetic chain producing less force.  This is the results of several factors including changes to length tension curves.  Simply stated, due to the altered mechanics, the muscles of the core and/or lower kinetic chain are placed in a shortened or lengthened position.  Knowing the impact that length (shortening or lengthening) has on force production, then the muscle cannot produce as much force or power as it could if it were in an ideal length tension relationship.

The indirect impact is after the injury occurs.  The altered biomechanics resulting in a non-contact ACL injury result in an impact on future athletic performance.  However, this concept of how these injuries impact future performance has not been fully investigated.  That said, more and more studies are starting to investigate the impact on future athletic performance.

Case in point, a recent study by Read et al, Am J Sport Med2017, the authors looked at the impact of ACL injuries have on future performance in National Football League (NFL) players. 

Methods:  38 NFL defensive players with a history of Anterior Cruciate Ligament Reconstruction
(ACLR) from 2006 to 2012 were identified.  For each injured player, a matched control player was identified.  For each player, demographic and performance data was collected.  Players that returned to play (RTPlay) after ACLR (N=23) were compared to players who did not RTPlay after ACLR. 

Results:  At least 74% (28/32) players who had an ACLR RTPlay in the NFL for at least one season game.  61% (23/32) successfully returned to play for at least half of the NFL season (min of 8 games).  In the seasons leading up to their injury, athletes who successfully returned to play started a greater percentage of their games (81%) and made more solo tackles per game (3.44 6 1.47) compared with athletes in the ACLR group who did not return to play.  Athletes in the ACLR group retired significantly earlier and more often after surgery than the matched control group.  In the season after ACLR, athletes who RTPlay started games 57% less times and had only 2.38 solo tackles per game compared to matched controls at 3.44 solo tackles per game.

Conclusion:  Athletes who successfully returned to play were above average NFL players before their injury but not after. 

Next week, we will start to dissect this a little more.  Specifically what does this mean to the team's performance as well as the athlete's overall earning potential.  If you are enjoying our blog, please share it and follow us on twitter @ACL_prevention and on Instagram at @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.