Monday, July 16, 2018

Psychological Measures for Return to Play Following ACLR - Part III

In this series we have been talking about kinesiophobia (fear of movement) and specifically how this is related to an increase in risk reinjury with athletes returning to play.  In the last blog, we provided a case study with an athlete that was being assess for return to sport specific testing. 

19 y/o female division I soccer player who is 5 months post op R ACLR.  She has been receiving "accelerated" rehab in an aggressive sport specific training center in Florida.  She is being assessed for return to sport specific training.  We are engaged by the team to do our movement assessments which is an aggressive movement assessment (ViPerform AMI) using 3D wearable sensors.  This test consist of:
  1. 1 minute Plank test
  2. Squat test
  3. 1 minute side plank right then left
  4. Single Limb tests all on right first then the left
    1. Single leg squat
    2. Single leg hop
    3. Single leg hop plant (multidirectional hop)
    4. Ankle lunge test


At the 5 month mark, most s/p ACLR should be able to perform the test.  Part of the pre-requisites for the test is that the athlete must have performed each of the movements safely in the clinic prior to testing.  When asked to do a single leg squat, you could visibly the athlete was hesitant to perform but did and safely.  When asked to perform a single leg hop, the athlete's hesitancy increased, she started sweating profusely and began to feel light headed.  This is an extreme case of kinesiophobia!  But why did she have this kind of response?  

This could have been avoided if several things had been done prior to the test.  
  1. Inform the athlete what the test will consist of prior to them arriving.  This athlete was unaware of what the test consisted of so the first time she was hearing about it was the moment she was asked to do.  
  2. Have the athlete safely demonstrate movements in a controlled environment prior to testing.  This is critical to see if the athlete is even at the point where testing is appropriate.
As simple as that sounds, neither of these were done in this case.  More importantly, the athlete had only begun to do single limb training a week prior to testing.  So, the athlete only began to do single limb testing just a week prior to testing and had never done single leg hops at all.  So, in the athlete's mind, this was not only the first time they had done this but also was similar to the mechanism by which they injured their knee initially.  No wonder she was having an extreme case of kinesiophobia.  She was set up for failure. 
Trends we have been seeing for the last several years in athletes with high levels of kinesiophobia are:
  1. The athlete tends to have a large lateral shift with bilateral squats where they are unloading the post operative side.
  2. The athlete has difficulty controlling how much their knee moves in the frontal plane during single limb testing
  3. The athlete has difficulty controlling the speed at which their knee moves in the frontal plane during single limb testing.
The first of our findings were confirmed recently in a study by Noehren et al Am J Sports Med 2018.  In this study the authors had athletes who were post op ACLR do a Tampa Scale for Kinesiophobia (TSK) and perform a drop jump from a 12 inch (30.48 cm) box onto a force plate.  What the authors found was that athletes who reported high levels of kinesiophobia on the TSK also unloaded their involved side during a drop jump test.  This is very similar to what we have been seeing with a lateral shift.  Athletes with higher levels of kinesiophobia demonstrate a shift away from the involved limb.  The problem with this is we would see this also carried over into their training.  So the athlete that demonstrates this in a body weight squat would also demonstrate this, sometimes even exaggerated, during a squatting motion under load.  So is it the kinesiophobia that leads to the shift or the shift that leads to the kinesiophobia?  Although we don't know this answer, we do know we can positively impact both.

The other two trends we tend to see, difficulty controlling amount and speed of frontal plane motion has not been proven in the research yet but is something that we see quite often.  This is also something that we are currently researching in our work in assessing athletes for return to play.  That being said, what we see is that athletes who have high levels of kinesiophobia have greater degrees os valgus during single leg squats, single leg hops and single leg hop plants.  What we also see is that these same athletes have higher speeds at which they fall into a valgus position during single limb testing.  

Taking the athlete pictured here, he reports a higher level of kinesiophobia and falls into valgus at >40  degrees per second in a single leg squat, >180 degrees per second in a single leg hop and >220 degrees per second in a single leg hop plant.  Considering these speeds should be 20 degrees sec in single leg squat, 100 degrees per second in single leg hop and 135 degrees per second in single leg hop plant, the athlete demonstrates speeds that are way out side the norms of what we typically see.  

This is great information to have but how do we change it?  Next week we will dive into how we can train an athlete to reduce a lateral shift, amount of valgus in single limb activities and speed and positively impact kinesiophobia.  We hope you have enjoyed this discussion and stay tuned as we continue the discussion.   #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 is also a competitive athlete in Brazilian Jiu Jitsu. 


Monday, July 9, 2018

Psychological Measures for Return To Play Following ACLR - Part II

Last week we learned that kinesiophobia (fear of movement) is bad, especially if an athlete exhibits kinesiophobia when returning to sport following an ACL reconstruction.  According to the Paterno et al Sport Health 2018 athletes who score 19 or above on the Tampa Scale for Kinesiophobia, they are 13xs more likely to reinjure themselves with return to play.  For those of us that have treated ACL patients, this is nothing new but we now have better ways of assessing it.  Rather than just being something we see anecdotally in our athlete, we now have tools, like the Tampa Scale for Kinesiophobia, where we can objectively measure this.  For a copy of this form, please refer back to our previous blog on 7/2/18.

But measuring kinesiophobia is one thing, what you do with that information is something entirely different.  One thing that can lead to increased kinesiophobia is an athletes lack of sport locus of control.  Sport Locus of Control is the athlete's feeling or perception that they are in control of their destiny.  For most athletes, throughout their athletic career, they have been in charge of their athletic destiny.  How hard they trained, their personal effort they put forth, how they performed as an individual or as a part of a team was determined by them.  However, once an athlete has an injury, many times for the first time in their athletic career, their sport locus of control is passed onto someone else.  It is the orthopedic surgeon that tells them when they can take the brace off, start running or return to play that has some of this.  It is the physical therapist or athletic trainer that tells them what exercise they can and can't do, how they will progress with running or sport specific activities that has some of this.  So, for the first time, the athlete is depended on others for their sport locus of control, for their sports destiny.  For many, this can have big psychological impact.  With that loss of control over one's destiny comes fear.  Ardern et al Am J Sports Med 2103, showed that sport locus of control was one of the indicators that determined an athlete's successful return to play.  Therefore, it is up to us to make sure the first thing we do is we give that back to the athlete.

Well that sounds easy but how do we do that?  There are several ways we can approach this, one is from what we say and one from what we do. 
It starts in the very first session.  I am often quoted as saying;

"I am simply an educator and a coach.  I will educate you about your injury, what the process is, what you should expect and how we will progress you for return to play.  I will coach you along the process, telling you what to do, how to do it and push you hard.  BUT at the end of the day it is up to you to make it happen.  This is not easy.  There will be challenges which we will overcome.  You have to want it.  It will define you as an athlete.  But you can do it.  You will do it and we will do it together.  You will come out of this faster, stronger and a better and more rounded athlete.  Are you ready and willing to make that happen?"

In that short 2 1/2 minute discussion, I have passed the sport locus of control to the athlete.  Psychologically, what was also done?  Two things:
  1. I gave the athlete confidence in me as the clinician.  Gaining the athlete's confidence in you as a provider is critical to their success.
  2. I gave the athlete confidence in themselves.  Confidence that they can do this, that they are in control and will determine their own destiny.
This immediate first step is critical to setting the pace for the entire rehab process and critical to building the patient's confidence.  The next thing we need to do early in the rehab process is start to build confidence in their ability to return to play.  Part of this is the conversation we just had and the other part is actually performing activities that provide you confidence that you can go the the next level. 

As common knowledge as we might think this is, what we find is that it is not as common as we might think.  A recent case highlights this. 

19 y/o female division I soccer player who is 5 months post op R ACLR.  She has been receiving "accelerated" rehab in an aggressive sport specific training center in Florida.  She is being assessed for return to sport specific training.  We are engaged by the team to do our movement assessments which is an aggressive movement assessment (ViPerform AMI) using 3D wearable sensors.  This test consist of:

  1. 1 minute Plank test
  2. Squat test
  3. 1 minute side plank right then left
  4. Single Limb tests all on right first then the left
    1. Single leg squat
    2. Single leg hop
    3. Single leg hop plant (multidirectional hop)
    4. Ankle lunge test
At the 5 month mark, most s/p ACLR should be able to perform the test.  Part of the pre-requisites for the test is that the athlete must have performed each of the movements safely in the clinic prior to testing.  When asked to do a single leg squat, you could visibly the athlete was hesitant to perform but did and safely.  When asked to perform a single leg hop, the athlete's hesitancy increased, she started sweating profusely and began to feel light headed.  This is an extreme case of kinesiophobia!  But why did she have this kind of response?  

We are going to dive into this case in some detail next week and specifically how we can avoid it with our athletes.  We hope you have enjoyed this discussion and we will continue with this next week as we evaluate how we can impact kinesiophobia and and additional scales we can use for return to play.   #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 is also a competitive athlete in Brazilian Jiu Jitsu. 




Monday, July 2, 2018

Psychological Measures for Return to Play Following ACLR

Over the history of this blog, we have focused a lot on movement and functional performance measures we should be doing with athletes to determine return to play.  Why is that?  Holm et al Am J Sport Med 2012 showed that 20% of athletes that return to play following ACLR re-injure within the first 2 years.  Further, Wiggins et al Am J Sport Med 2016 showed that one in four youths who tear their ACL will suffer another ACL injury at some point throughout their athletic career.  With odds like this, we have to do something to help improve the odds and more importantly protect our athletes as they prepare to return to play.

Traditionally and in a majority of athletic settings, return to play means just assessing the athlete's strength and endurance and maybe performing some movement assessments or functional assessments.  However, all too often we forget about the psychological factors that are associated with return to play.  In the last couple of years however, there has been a tremendous amount of work done in this area. 

One of the most common aspects talked about when determining return to play is kinesiophobia or fear of movement.  Amy times, as the result of the athlete's initial injury, there is a lack of confidence in the injured limb and therefore a fear of reinjuring upon return to play.  There has been several studies in the last couple of years that show that athletes that have higher levels of kinesiophobia are in fact at greater risk of injury.  In a systematic review done by Everhart et al in Knee Surg Sports Traum Artho 2015, the authors showed a high correlation to kinesiophobia and re-injury rates in ACLR patients.  In a recent study by Noehren et al Orth J Sport Med 2017 the authors looked at athletes that were returning to sport and for those that demonstrated kinesiophobia if there was any correlation to the way they moved and potential injury risk.  What the authors found was that athletes that demonstrated higher levels of kinesiophobia demonstrated lower weightbearing in the reconstructed limb. 

Although assessed differently than in this study, this is a similar pattern we see, especially when assessing an athlete's squatting motion.  What is demonstrated is a significant lateral shift to the contralateral limb (uninvolved side) and away from the involved side.  The authors of this study found similar results where the athlete was shifting their weight to the univolved side during vertical jumping and landing activities.  The authors compared these results to a measure of kinesiophobia and found a strong correlation between the two.  Meaning athletes that shifted weight away from the involved side scored high on the kinesiophobia scale.

With all the studies coming out showing similar corelations with risk and kinesiophobia, then how do we measure this in our athletes?  Is this an overally complex measure and is this something that requires a psychologist to do?  The answer to both those questions is no.  Simply, we can implement at Tampa Kinesiophobia Form as a part of our evaluation process.  For those that have not seen it, the Tampa Scale is below is scored on a 1-4 scale for each question.  A total score is calculated after inverting the individual scores on 4, 8, 12, and 16. 
Adding up all the scores and dividing by the total possible score (68) points.  Higher the percentage the higher the individual's kinesiophobia or fear of movement.   Paterno et al Sport Health 2018 showed that athletes who have a score of 19 (27.9%) or greater at the time of RTPlay are 13 times more likely to suffer a second ACL injury.  Based on the findings of Noehren et al, that makes sense.  Based on those studies, one could hypothesize that the higher the percentage of kinesiophobia then the greater the displacement would be to the contralateral or non-involved limb. 

Based on these results, it is high suggestive that this type of form be used in helping us make a return to play decision for our athlete.  We hope you have enjoyed this discussion and we will continue with this next week as we evaluate how we can impact kinesiophobia and and additional scales we can use for return to play.   #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.  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 is also a competitive athlete in Brazilian Jiu Jitsu. 




Monday, June 25, 2018

Assessing Risk - Is it Possible Part VII

Throughout the course of this blog, we have touched on a lot of different topics about assessing risk in an athlete, from what we need to assess, to how we assess, to what we need to address psychologically when assessing and treating.  Lastly, we need to know how do we change what we assessed.

As easy and simplistic as that sounds, it often the most difficult aspect of what we do.  I am blessed to meet physical therapists, athletic trainers  and strength coaches from all over the US.  When I ask them, do you change movement in your athletes I get resounding yes.  But, do we really change movement in our athletes and how do we know that?  The first step to knowing is measuring correctly.  We don't know if we truly change movement unless we measure it correctly.  That is why technologies such as the ViPerform AMI are so important.  This allows a valid, reliable and sensitive measure of how an athlete moves.

In my role, I have the unique ability to travel all over the US and abroad to assess a variety of athletes for how they move.  Whether that is a part of physicals or basic training, assessing for return to play, implementation of a program or simply teaching medical teams how to implement with their team, I am afforded a wide variety of experiences.  What I see is that we often think we change movement however when truly assessed what we find is that the final outcome on movement is less than what we would desire.  Therefore accurately measuring baseline movement is the essential starting point. 

Once we do this, we can then test varying intervention strategies and see, does this change the baseline movement assessment we did.  Simple right?  As simply as it sounds, it is often where we miss the mark.  For all too often, we want to get overly complex in our strategies and miss the simplicity of simply addressing what we know.  What do we know?  Earlier in this blog series, we discussed the importance of measuring dynamic valgus.  According to Johnston et al Am J Sport Med 2018 we need to develop assessments that measure dynamic valgus and interventions which train control of dynamic valgus in single limb performance in professional athletes.  Further Owusu_Akyaw et al Am J Sport Med 2018, demonstrated there is a similar mechanism of injury in younger athletes and therefore the same applies to the younger athlete.  So, we must control dynamic valgus.  We must train that in simple tasks and build it up to more and more complex tasks once perfected in simple tasks.

In words, it sounds simple.  Lets take an example here.  Whether this athlete is a wrestler or mixed martial artist, there is an impact to both performance and risk.  Based on baseline assessment we see during his single leg activities that he has a large dynamic valgus which are occurring at high rate of speeds.  We know this will not only increase his risk for injury, but we also know this impacts his performance.  As he shoots in on his opponent the larger the valgus that occurs and the higher rate of speed will result in a loss of power that he will hit his opponent with and the speed to take down will be impacted.  Despite the fact that his team is doing a lot of training to improve his movement, this is still persistent.  Why?

When looking at his training, it is comes down to not what he is doing but how he is doing it.  This same athlete is doing a lot of core training and single limb training which should impact his movement.  It is a similar program we might deploy with him but with very different results.  What is the difference.

Let's just look at a couple of examples.  Dynamic lunges.  This is an exercise we often deploy as way of warming the athlete up for athletic participation.  In addition to being a great mobility exercise, this is also a great neuromuscular preparation exercise.  During this motion the athlete must control the knee from moving into a dynamic valgus position throughout a large range of motion and movement of the center of mass through a large displacement.  The technique for the exercise is as described here.



Performing the exercise  in this fashion and repeatedly in training sessions optimizes carry over to sport.  However, what we seeing being performed is a similar exercise but one that emphasizing dynamic valgus repeatedly with every repetition.  Although it is hard to see from this angle, what you see is the athlete's right knee moving into a dynamic valgus with every repetition.  Doing this in a semi-rested state (beginning of practice or training session) will mean that the athlete will do this when they are fresh in the round or game and even more so when they are fatigued.  This same movement will also then carry over to more complex and explosive movements like take down, exploding off the line, or sprinting down the court.

In addition to this exercise, we also see core training also being implemented with these athletes.  We know this is a critical component to improving an athletes overall movement, reducing injury risk and improving performance.  One of the exercises we commonly recommend is the sideplank exercise.  This exercise has a high EMG activity for the gluteus medius and the entire core.  Our goal with this is to be able to have the athlete maintain the proper position during the exercise which means not moving the hips up or down or rotating in the spine.  The technique for the exercise is described here.


In this exercise we start with 10 seconds and build this up to a 1 minute hold.  Maintaining this position without the hips raising up, dropping or rotating, ensures that the gluteus medius and the entire core is active throughout the exercise.  Complexity can be added to this exercise with the addition of the Theraband CLX band which brings in the entire core in a cross sectional fashion.    However, what we see when observing our athlete doing this exercises is different than what is described in the video.  What we see here is the athlete attempting to perform the same exercise but doing so with raising his hip up.  What happens is the gluteus medius on the down side is now placed in a shortened position which results in a significant reduction in EMG activity from one of the major muscles we are attempting to target and train.  More importantly, this same training technique then carries over into single limb performance.  What we then see is that the training impact is that the athlete has either a dynamic valgus in single limb activities or they have a loss of pelvic control during single limb activities.  Either way, the net result is a negative impact on performance and injury risk.

The intention here is not to say that these exercises are the end all be all (however we have shown this series of exercises to dramatically reduce injury rates in DI Sports - see FOX STORY).  Instead, we all know there are a 1000 ways to train movement.  However in our desire to strive for the most creative ways to address, we lose the simplicity of what we need to do.  Train single limb, train to control valgus and speed of valgus and train with proper form.  Once able to do with simple tasks, move to more complex.  Period.  If we simply do that without all the complexity of super sophisticated exercises we might see better results when comparing to our baseline assessments.

We hope you have enjoyed this series and looking forward to sharing with you our continued passion in our next series.  Please make sure to check out our new website at www.iceperform.com where our goal is to help you help others.  #ViPerformAMI


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 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 is also a competitive athlete in Brazilian Jiu Jitsu. 




Monday, June 18, 2018

Assessing Risk - Is it possible Part VI

Last week, we discussed, according to the research, what we need to assess as well as the importance of video.  We now know that video is an important component of an assessment as well as helping an athlete correct faulty movement patterns. 

In addition, providing video feedback, we also need to look at additional factors that result in compensatory strategies that were identified in the Wren et al study.  Hartigan et al J Ortho Sport Phy Ther 2013 looked at Kinesiophobia (fear of movement) prevalence in ACLR athletes.  What the authors found was that a lot of athletes scored high on the Tampa Scale for Kinesiophobia following ACLR.  This is a research based valid measure of fear of movement in athletes.  Whether it is the chicken before the egg or egg before the chicken, what we do know is that athletes high high Kinesiophobia move differently.  They are more hesitant to move to the involved side, tend to shift their weight away from the involved side and have less control of the limb in single limb activities.  So is it the subconscious awareness of the movement or lack of stability that creates the fear or is it the fear that creates the lack of stability.   Sadly there are a lot of athletes that are discharged from PT who still demonstrate a lot of kinesiophobia.

The answer is not real clear.  What we do know is that you can train them out of it.  Before I knew what kinesiophobia was, the young athlete pictured here presented to my office for a return to play (RTPlay) assessment.  During his history he stated:

  1. I am not confident moving to that side
  2. That side does not feel the same
  3. I don't feel like I am as strong on that side
  4. I am nervous cutting to that side.
These are all classic signs of kinesiophobia.  But what we found during the exam was this same athlete demonstrated one of the largest lateral shifts I have seen (>3 inches away from the operative side) during a squat.  In addition, his single limb test demonstrated a lack of control of valgus in loading and landing as well as a significant variance in vertical hop on the involved versus the non-involved.  So was it his lack of stability and motion causing the kinesiophobia or the kinesiophobia causing the motion.  Most likely it is a combination of the two but both which can be addressed.

What we know is that this starts with providing the athlete with Sport Locus of Control in the visit #1.  Ardern et al Am J Sports Med 2013 showed that athletes who have had an ACLR have relinquished this sport locus of control to the health care provider.  So what the heck is that and why does it matter?    As an athlete, who is in control of your destiny as an athlete?  Who controls how hard you work?  Who determines how hard you practice?  Who determines how much you effort you put out on the field.  Ultimately, who determines you success in sports?  The answer in most cases is you, the athlete.  You are in control of your destiny.  You have the sport locus of control.  You are in control of your destiny in sports.

Following an injury or ACLR, the athlete, many times for the first time, reliquish this sport locus of control to the health care provider.  So suddenly someone else tells them what they can do at the gym, when they get off crutches, when they can start doing drills, practice with or without a brace and when they can get back to sport.  In other words, someone else has the Sport Locus of Control.  This lack of control can lead to depression and can add to kinesiophobia.  So, it is vital that we give that control to the patient in visit 1.  I am often heard saying, I am simply a coach and an educator, I will coach you along the process and educate you why we do what we do but at the END OF THE DAY IT IS UP TO YOU!  In that one sentence, I am passing the sport locus of control over to the athlete.

In addition to passing the sport locus of control onto the athlete, we must also think through how we can impact kinesiophobia starting immediately in the first visit.  What we have found that works very well is:

  1. Educate the athlete why you do what you do - they are much more likely to do if they know why.
  2. Pair with other ACLRs who are later in the process.  This will create conversations and they will see how far along they will be in 3 weeks, 2 months, 4 months - it is encouraging.
  3. Start full weight bearing as soon as possible.  This will help to normalize gait, aid in reducing qua atrophy and reduce risk for lack of TKE with gait.
  4. Start single leg activities as soon as possible.  This is NOT balance but things like single leg squats, single leg hops, etc.  This will build confidence.  
  5. Push quality over quantity.  We know it is the magnitude and speed of valgus that cause injury.  Make sure they control that throughout the range of motion prior to proceeding.  
  6. Make them work hard.  Push them hard but safely.  People are often amazed at what they can achieve.  
Take a look at this still taken from an Olympic athlete that had been dealing with an injury.  She was reporting loss of confidence on this side as well as loss of explosive power.  Despite months of rehab and working with sprint coaches, and strength coaches, these movements remained.  By providing her visual feedback (via video), educating her on, giving her the control training her hard to prevent, not only is she able to run pain free but also is performing at a higher level.

Too touchy for you?  Me to.  Next week we will talk about specific training to control dynamic valgus.  Please make sure to check out our new website at www.iceperform.com where our goal is to help you help others.  #ViPerformAMI



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 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 is also a competitive athlete in Brazilian Jiu Jitsu. 

Monday, June 11, 2018

Assessing Risk - Is It Possible Part V

During the last couple of weeks, we looked at a recent study published by Wren et al J Orth Sports Phy Ther 2018.  In this study the authors looked at hop distance symmetry as a predictor of lower limb biomechanics.  The authors found hop distance is not a predictor of biomechanics and that the athletes tend to compensate on the non-involved leg.  As we began our discussion we talked about how this happens in our athletes and what we must do to prevent.

Last week, we began discussing mental compensation (kinesiophobia) and lack of training as a potential cause for this being a pattern that athletes continue with even when they return to play or post rehabilitation.  It is suspected or hypothesized this could be one reason that athletes continue to be at greater risk of re-injury (Wiggins et al Am J Sports Med 2016) or osteoarthritis 12 years later (Holm et al Am J Sports Med 2012).  As a physical therapist, athletic trainer or strength coach, there is a lot that we can do to change these odds.  First, we have to know what to look for.

In our last series, we discuss the Johnson et al Am J Sports Med 2018 paper where the authors identified the mechanism for non-contact ACL injuries in professional football players.  This led the authors to suggest there was a need to develop programs that assess and assist athletes to control this dynamic valgus position.  Although this is relevant for NFL players, is this also relevant for our younger college and high school players?  Owusu_Akyaw et al Am J Sports Med 2018 looked at the mechanism of injury in male and female athletes ranging from 15-30 years old.  Although the authors did not have video analysis available for all injuries, they were able to identified the position of the articular surfaces at the time of the injury by evaluating the bone bruising that was present on the surfaces.  Based on biomechanical models, this reveals a similar dynamic valgus position at the time of injury.



Considering, we must then assess this.  There are a lot of ways to do this.  You can do with a variety of movements and variety of technologies.  For our athletes, we use the ViPerform AMI (powered by DorsaVi) due to the fact that it has a progressive routine of single limb tests.  This assesses the ability to stabilize in single limb and it is measured with an inertial measurement unit and video.  The IMU provides accuracy of measurement within 3% of a Viacom system and the video provides a medium for providing feedback to the athlete.


As we mentioned in the previous blog, assessing both the magnitude of motion and speed of motion is critical when looking at risk.  Keep in mind, the ACL is about the size of your pinky.  It takes 21.5 N of torque (rotation) to rupture and 250 kg of force.  In a closed kinetic chain, the more valgus that occurs at your knee the more torque that is imparted to the ACL (with larger degrees of valgus comes internal rotation in a closed kinetic chain).  In addition, force is determined by both the amount of motion that occurs and the speed at which that motion occurs.  Therefore, assessing only the amount of motion is only half the picture, you must also look at the athlete's ability to control the speed at which that motion occurs.  With IMUs, you can capture not only the amount of motion that occurs but also the speed at which that motion occurs.

Why is video feedback so important?  Agresta et al J Ortho Sport Phy Ther 2015 performed a systematic literature review looking at common movement patterns present in runners that predisposed to injury and effective ways at which change that.  What this study found was that providing video feedback helped the athlete make immediate changes to their running patterns.  What we have found is that video helps in several ways:


  1. Showing an athlete how they move on video is a very effective tool to helping them understand the complexity of and relation to impact on sport
  2. Showing them a video of them moving has an immediate impact on their buy in to what you are telling them and their overall compliance.  

So, this was a really long way around approaching how we can use this in our training.  Providing video feedback is critical first step in training the athlete.  It starts with the assessment.  Showing the athlete how they move during single limb performance and during fatigued state.  This will assist in the immediate buy in and help the develop a better kinetic sense of the movement.   In addition, this will also assist in further training down the road when we are cuing them on correctives.  They will be able to correct the movement faster without the need for external visual input since they got this earlier in the rehabilitation or training routine.

Next week, we will continue our discussion on use of video in our assessment as well as how to address athletes subconsciously avoiding that involved side.  Please make sure to check out our new website at www.iceperform.com where our goal is to help you help others.  #ViPerformAMI


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 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 is also a competitive athlete in Brazilian Jiu Jitsu. 

Monday, June 4, 2018

Assessing Risk - Is It Possible Part IV

Last week, we looked at a recent study published by Wren et al J Orth Sports Phy Ther 2018.  

Hop Distance Symmetry Does Not Indicate Normal Landing Biomechanics in Adolescent Athletes with Recent Anterior Cruciate Ligament Reconstruction. 


The following conclusions came out of this study.  Both symmetric and asymmetric patients offloaded the operative knee and symmetric patients achieved symmetry in part by hopping a shorter distance on the contralateral side.  Therefore, hop distance symmetry may not be an adequate test of single limb function and return to sport readiness.

Discussion:  Let's take a little further look at the results.  The first result, asymmetrical patients did not jump as far on the operative side, is expected.  If an athlete has asymmetry in this test (which is a measure of distance jumped on the operative leg compared to the contralateral side), then hopped shorter distance on their operative limb and are therefore asymmetrical.  That is why, in this test, they would be asymmetric in the first place.  So no big revelation there.  

The other result, symmetric patients achieved symmetry in part by hopping a shorter distance on the contralateral side.  This test is designed to be a way to assess limb symmetry index or the variance between the right side and the left side.  Studies have shown (Rhoman et al Am J Sports Med 2015) that norms have a limb symmetry index of 85%.  Considering this, it is hypothesized if an athlete has a variance >15% on the right versus the left, then they are at greater risk of injury.  Based on the results here, we can make the assumption that this test will not show us who is at risk.  Whether consciously or unconsciously, the athlete is modifying effort on the non-involved limb which will misrepresent the true limb symmetry index. 

However, the area of biggest focus for most of us is what are the biomechanics at take-off and landing?  As the athlete is going into loading the limb for explosive power and begins to explode up, it is usually the transition from loading the limb to explosive movement that you will see the knee move into the dynamic valgus position.  This is a focus for most as we know that this motion is the one that will or could potentially lead to increase risk for ACL injury or mensical injury. 


If you take the above slide as an example, you will see that based on basic biomechanics that force is determined by both the magnitude of the motion (how much the knee moves into valgus) and speed (how fast it moves into valgus) at which that motion occurs.  So the larger the valgus is at loading and the faster that valgus occurs at loading, the greater the risk is that force will be departed to the ACL and the meniscus.  This is something we want to measure and quantify.  According to Johnston et al Am J Sports Med 2018, based on video review of non-contact ACL injuries in football players, dynamic valgus is the position that causes ACL rupture which led the authors to suggest this should be something that is assessed to identify those at risk. 

This same motion is typically observed again at landing.  When the athlete’s foot contacts the ground and they have to being to attenuate the force through the foot/ankle, knee and hip.  It is typically at this point under high loads that you will again observe the knee move into the dynamic valgus position. Considering the ground reaction forces generated in landing (on a basketball court) is anywhere from 4-8 times body weight, we can understand the importance of controlling this motion during these movements.

This study also showed there was lower knee flexion moments and subsequent decrease in energy attenuation along the system.  We see this a lot in athletes following an ACLR and think a lot of this has to do with mental compensation and lack of training. 

First let’s look at mental compensation leading to lower knee flexion moments.  What we suspect in these cases is the athlete subconsciously knows they lack the control of the knee to prevent dynamic valgus at larger knee flexion angles.  This is a position that gives them a lot of fear (kinesiophobia - fear of movement) since they subconsciously know this is the position during which they tore their ACL.  As a result of the fear, they will subconsciously compensate and not allow themselves to fall into larger knee flexion angles because they loose control.  If they allow greater flexion angles during the landing phase then they will fall into this dynamic valgus motion and potentially rupture their ACL.  If this is not addressed (through out their rehab and return to play) then this adds to greater ground reaction forces being distributed to the knee, hip and low back.  This will break down tissue and potentially result in additional non-contact injuries.  In addition to this, it can also add to a lack of force production.  Most will demonstrate both in landing and take-off.  In take-off, by decreasing flexion angles, this results in a decrease in force production and power output.

Next week, we will look at the lack of training and how this leads to decreased knee flexion angles.  Please make sure to check out our new website at www.iceperform.com where our goal is to help you help others.  #ViPerformAMI



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 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 is also a competitive athlete in Brazilian Jiu Jitsu.