RTPlay Following ACLR - How Do We Know When Is The Right Time? - Part III

Last week, we concluded our discussion talking about Melick et alBr J Sport Med 2016 systematic review that provided guidelines for RTPlay based on the most current evidence.  Specifically, we dove into the topic of LSI or limb symmetry index.  The systematic review suggest that looking for an LSI of >90% of the non-involved limb was a criteria we should consider.  This led to Rohman et al Am JSport Med study which showed that 93% of non-injured norms had an LSI of 85% or greater.  This may make us question whether or not we might be setting the criteria to high.  Is 90% realistic if 93% of non-injured norms are 85% or greater?

We also brought up the concept of what happens to the non-involved limb during the rehab process?  We all know those athletes are less active during rehab than they are during their sports participation.  So, are we comparing the injured side to a deconditioned side?  If we are, is this a good measure of LSI for determining someone’s ability to safely return to play?  In the Rohman et al Am J Sports Med 2015 they looked at 122 ACLR athletes.  In this study they performed single limb testing on the involved leg and non-involved leg pre-operatively and post operatively. 

To measure LSI, based on literature review, the authors choose several tests.

1.     Balance – single leg anterolateral reach, single leg anteromedial reach, stork stance eyes open and stork stance eyes closed.

2.     Strength – retro step up and single leg squat

3.     Functional testing – single leg hop, single leg triple hop, cross over triple hop and timed hop

4.     Core – plank and single leg bridge

Based on the results, the authors found that the best measures for determining LSI are the single leg squat, single leg hop, retro step up, cross over triple hop and the timed hop.  This is one key take home for all of us.  Inclusion of these tests or portion thereof should be considered when we are looking to put together our RTPlay assessment.  The other finding that  was very telling was the measure of post-operative LSI.  The results of this study indicate the LSI measures performed on the non-involved leg showed there was significant deterioration of the non-involved extremity from pre-operative measures to post-operative measures.  This means if we are using the post-operative non-involved leg to compare to, then we are comparing this to a deconditioned limb and may not be truly assessing the risk that is associated with RTPlay. 

Based on this information, this led the authors to suggest the use of absolute LSI.  Absolute LSI is defined as:

Absolute LSI % = Post-operative leg LSI measures / Pre-operative non-involved leg x 100

As we discussed last week, as clear cut as the Melick et al study appeared to be, we can now see that may not have been the case.  Based on these two Rohman studies we now know some tests that we should consider for measuring LSI and what we should compare the involved limb to for determining the absolute LSI.  However, this still does not answer another fundamental question we may have with these tests.

If someone’s ability to do a single leg squat, single leg hop or a cross over hop and they are able to do this within 90% or 95% of their absolute LSI, does this mean they are not at risk?  Does simply having the ability to perform 10 single leg squats bilateral, or perform 10 hops or 10 cross over hops all within 90% or > of their non-involved limb tell me they are not at risk?  Is risk associated with just the ability to do alone?  Can you perform this movement and be 100% of the non-involved leg and still have horrible movement that would put you at risk?  I think we all intuitively know that answer and yet the tests we use do not typically account for that.  

Next week, we will start to dig into just this concept by looking at what should we assess and what does the studies tell us about functional testing.  If you enjoy this blog, please share with your colleagues and follow us on instagram @ bjjpt_acl_guy and twitter at @acl_prevention.  #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, 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 has also been training and a competitive athlete in Brazilian Jiu Jitsu for 5 years.