Neuroplasticity and ACLR Rehabilitation

One of the most challenging aspects of treating athletes who have had an ACLR comes at the conclusion of rehabilitation when we are attempting to make that final return to sport decision. Throughout the rehab process, we do everything we can to ensure that the athlete is physically and mentally ready for return to sport. We hope that the training methods we have implemented have prepared them for this. But what if I told you there is an aspect that we typically miss.

Have you heard of neuroplasticity?  Defined, neuroplasticity is the ability of the brain to form and reorganize synaptic connections, especially in response to learning or experience or following injury.  This has become an area of increased focus in ACLR because we know there are changes that occur in the higher centers (brain) after an ACLR.  If these changes are not addressed as a part of our rehab, then they can remain and increase the athlete's risk of reinjury with return to sport (RTSport).  At this point you may be saying to yourself, not my patients.  With the functional training that I do, by the time they are ready for RTSport, we have addressed this.  Have you?

Some recent studies have highlighted a sobering fact.  We are not as good as we think we are.  King et al Am J Sport Med 2019 performed 3D motion capture on 156 athletes that were 9 months post op ACLR and compared those to healthy controls.  The subjects performed:

• Bilateral vertical drop jump test
• Single leg vertical drop jump test
• Single leg hop for distance
• Planned and unplanned change in direction task

What the authors found was there was an asymmetry in loading in the bilateral vertical jump test and greater asymmetries in single limb testing.  Considering all these athletes had gone through rehabilitation and were progressed for RTSport, there was obviously something missing in the rehab process that allowed this degree of asymmetry to continue to exist.  

When you look at athletes who have gone back to sport and who are doing some kind of strength and conditioning with the team, then surly this must be corrected and resolved.  Ithurburn et al Am J Sport Med 2019 took this one step further and looked at athletes who had RTSport and were 2 years out post ACLR.  In this study, the authors looked at 64 male and female athletes and did 3D motion capture during bilateral and single limb vertical jump testing.  What the authors found was bilateral vertical jump test significantly improved with improved symmetry but single limb vertical drop jump test still demonstrated significant asymmetry.  

So despite going back to their normal routine, sports, sports training, weight lifting, etc, there still remained a significant deficit that puts that athlete at a greater risk of reinjury.  So what are we missing?  One, we need to do a better job of testing "biomechanical" factors throughout the course of rehab to ensure the interventions we are doing are in fact positively changing these.  But two, we need to make sure we are addressing the neuroplastic changes that occur.  

Neuroplasticity also known as brain plasticity or neural plasticity is the ability of the brain to change throughout one's lifetime. We know, for example, in stroke patients, that the brain has the ability to adapt and change as a result of the neural insult to the brain and can remap neural pathways so that non-damaged areas can take on some of the function of the damaged sections. That is neuroplasticity. In neuro rehabilitation settings we know this and can deploy certain techniques that will aid in this facilitating this process or neural adaptation in the brain. This aids to improved function despite the initial neural insult. In sports medicine, we rarely think about the changes that occur in the higher centers (in the brain) with an orthopedic injury.

However, next week, we will start looking at some recent studies, like the study by Grooms et al J Orthop Sport Phys Ther 2017 which highlights some of these neuroplastic changes that occur post ACLR.  This will lead into some specific training and programming we can do to change.  Stay tuned as I am super excited to share with you.

Have you followed my instragram @bjjpt_acl_guy lately?  If not, you are missing out.  I am constantly posting the latest research in injury prevention and sports medicine.  Don't miss out and please share with your colleagues, athletes and training partners and please be sure to follow us on instagrm @ bjjpt_acl_guy and twitter @acl_prevention.  Train hard and stay well.  #ViPerformAMI #ACLPlayItSafe

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 and ACL injury prevention.  He is the founder | developer of the ViPerform AMI,  ViPerform AMI RTPlay, the ACL Play It Safe Program, Run Safe Program and author of a college textbook on this subject.  Trent has performed >5000 athletic movement assessments in the US and abroad.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Vice Chairman of Medical Services for USA Obstacle Racing and movement consultant for numerous colleges and professional teams.  Trent also a Brazilian Jiu Jitsu purple belt and complete BJJ/MMA junkie.