Monday, January 14, 2019

Improving Movement When It Matters - Part IIID

Last week we continued our discussion about the importance of single limb training and how ankle range of motion and control can impact that.  As we continue that discussion and move up the chain, we now start to look at the knee. 



Knee
When performing movement assessment, we often get hyper focused on frontal plane motion only at the knee.  As described in the above example, this can often lead to missing the "root cause" of the dysfunction and less effective treatment strategies.  If we treated the two examples above exactly the same, then we might have a less effective treatment and potentially not address the true "root cause".


If we look at this example more closely, what we see is that the knee begins to cross midline prior to:

  • Movement of the foot into a pronated position - root cause being more at the foot and ankle
  • Movement of the pelvis into a trendelenburg or corkscrewing position - root cause being more at the core
When we are seeing this motion being driven from the hip complex (frontal plane motion of the knee in the absence of excessive pelvic motion or pelvic motion) this can indicate is weakness in the gluteal region, specifically the gluteus medius and maximus.   This is where exercise targeted to this region can be very effective. 

Glut Med Series:




Use of this exercise allows us to target to the glut medius specifically.  As indicated in the video, position of the feet is critical for those with weak gluts will toe out during this exercise which will limit the strengthening that occurs at the hip.

Single Leg Lumbar Hip Disassociation:


Due to the fact that we don't know if this is associated with weakness/endurance issues in the muscles of the hip or proprioceptive issues in the hip, using this exercise targets both strength/endurance as well as proprioception.  When done properly with proper hip positioning, we find this results in significant increase in EMG activity of the gluteus medius.

Next week, we will conclude this discussion on single limb training with our examination of what is going on at the hip. 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. 



Monday, January 7, 2019

Improving Movement When It Matters - Part IIIC

Last week we talked about the importance of single limb training and how, by using a criterion based approach, we not only impact kinesiophobia and strength, but also drive improvements in movement that have much higher carry over to sport.  Before we move off the subject of Single limb training, there are several things we need to talk about.

In a criterion based approach, in order progress from one level to the next, we must be able to perform the prior level with good technique.  What exactly does that mean?  This means one must be able to perform the exercise while demonstrating good control at the:
  • Foot and ankle
  • Knee
  • Hip

Foot/Ankle Range of Motion
Starting at the ground and moving up, let's first look at the foot and ankle.  First in order to have good control of the foot/ankle, you must first have adequate range of motion at the ankle.  When looking at the literature, there is not a lot of literature letting us know how much motion at the ankle does an athlete need to do a single leg squat or single leg hop.  So in one of our recent studies, we looked at ankle dorsiflexion in over 700 injured and non-injured athletes.  Looking at the non-injured athletes (N=300), we found the mean ankle range motion to be following:


The mean range of motion for dorsiflexion for single leg squat was 33 degrees and those that had scored lower (higher risk and/or injured) had a mean range of motion for dorsiflexion <20 degrees. 


For a single leg hop, the mean range of motion for dorsiflexion was 30 degrees and those that had scored lower (higher risk and/or injured) had a mean range of motion for dorsiflexion <15 degrees.  What we can take away from this is that we should shoot for 30 degrees or > dorsiflexion range of motion for someone to perform a single leg squat correctly with good form.  So from a criterion based perspective, 30 degrees or > dorsiflexion could then be a criteria we consider prior to starting of single leg squatting activities in order for someone to do it right with proper technique.

When dorsiflexion range of motion is an issue, aside from the traditional exercises we do, there are also some dynamic stretches we can do that will aid in driving improvement in dorsiflexion range of motion in full weight bearing, in a closed kinetic chain and during motion. 

Dynamic Sumo:


In this dynamic stretch, you will see throughout several portions of this exercise we are pushing DF range of motion that is much greater than 30 degrees of dorsiflexion throughout various ranges of motion of the proximal links. 

Dynamic Lunge:



In this dynamic stretch, we continue to push dorsiflexion ranges of motion exceeding 30 degrees throughout various portions of the movement.  If you have an athlete with limited DF, this will typically result in predictable movements that are easily observed. 

Foot/Ankle Stability
In addition to range of motion at the ankle, having the neuromuscular control at the foot and ankle is critical injury prevention and whole kinetic chain stability.  Yet, this is often a movement that is missed in most movement assessments. 


As you can see from this picture, when just looking at the knee, this looks like a valgus or frontal plane motion at the knee.  Yet in one picture, we see the hip fall first and in the second picture, we see the foot fall first.  Why does that matter?  Same athlete yet the training will be considerably different on the right side versus the left side.  On the athlete's left side, we can see we need to do more ankle, intrinsic and foot/ankle proprioception versus the hip strengthening and proprioception on the athlete's right side. 

Next week we will continue this discussion and talk about the impact at the knee and hip.  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. 

Monday, December 31, 2018

Improving Movement When It Matters - Part IIIB

Last week, we discussed why we should consider doing single limb training as a normal part of our performance training but also as a part of our return to sport.  Laying out exactly how one should progress through single limb training is very dependent on the what type of procedure has been done and the physician's protocol.  The information provided here should never be considered in place of advice or recommendations provided by your health care professional.

In health care, there are typically two schools of thought related to progressing an athlete along a continuum.  One which is much more of a medial model/physician based approach is a time based approach.  The athlete will progress to running or plyometrics once the tissues are healed to the point that they can withstand the associated stresses and loads with those activities.  However, many times the tissues may be ready but the neuromuscular and muscular system may not be ready for those kinds of activities. 

The other approach is more of the athletic training/physical therapy based approach which is the criterion or movement based approach.  Once the tissues are healed and ready to withstand the associated stresses, the athlete is not progressed until they are biomechanically sound with the previous lower level or complexity of movements.  The following discussion follows along both of those continuums and however we will only discuss the movement criteria needed for progression. 

In the realm of single limb training, following a criterion based or movement criterion based approach is critical to ensure we are not re-training poor movement patterns but training proper movement patterns.  Although someone's tissues may be healed to the point that they can attempt certain movements does not mean that they are necessarily ready to start said movements.  By following this approach, we are also putting positioning the athlete for a safer return to sport. 

Following is a simple progression for low levels of single limb training to more aggressive levels of single limb training along with some criteria that we can use to make sure one is progressing safely from one level to the next.  This is by no means a comprehensive progression but can provide some ideas on how to progress.

Level I - Partial weight bearing (PWB)  - weight shifts to single leg stance & single leg press
  • Once cleared to start PWB we will typically start weight shifts.
  • Once cleared to start WBAT, we will start full weight shifts to single leg stance
    • Criteria to progress - perform single leg stance without trendelenburg or retrotrendelenburg and without movement of the knee in the frontal plane.
  • Once cleared to WBAT, start single leg press at 20% body weight and progressing up from there
    • Criteria to progress - perform full body weight leg press without movement of the knee in the frontal plane.
Level II - Full weight bearing (FWB)
  • Once cleared to FWB start body weight squats through partial to full ROM.
    • Criteria to progress - perform full ROM body weight squat without lateral shift (shift away from the affected limb) and without movement of the knee in the frontal plane.
  • Standing Gmed (use affected leg as the stance leg) with theraband.
    • Criteria to progress - perform 20+ reps with green theraband without trendlenburg or retrotrendelenburg at the hip and without movement of the knee in the frontal plane.
  • Standing Gmed Isometrics (used affected leg as stance leg) against a wall.  Alternate angles 30 - 45- 90 - 110.
    • Criteria to progress - perform 20+ reps at varying angles without trendelenburg and without movement of the knee in the frontal plane.
Level III - Prior to running
  • Single leg squats - progressing partial squats to 45 degree squats.
    • Criteria to progress - symmetrical knee flexion during squats, no trendelenburg/retrotrendelenburg and without movement of the knee in the frontal plane.
  • Dynamic Lunge - progressing from dynamic lunge stretch to full lunge exercise.
    • Criteria to progress - symmetrical motion bilateral, no movement of the knee in the frontal plane with step through and good hip extension bilateral

  • Side stepping with Theraband
    • Criteria to progress - perform 20+ reps with keeping feet pointed straight


  • Single leg lumbar hip disassociation with Theraband
    • Criteria to progress - perform 20+ reps without trendelenburg, retrotrendelenburg and without movement of the knee in the frontal plane.

  • Single leg hop
    • Criteria to progress - perform 10-15 reps without trendelenburg, retrotrendelenburg and without movement of the knee in the frontal plane.

This is just one example of a progression and some of the criteria used to determine what should be accomplished prior to progressing to the next level.  There is a plethora of exercises that could be used in place of these but the concepts should be the same.  You train the movement you want.  Train trendelenburg or movement of the knee in the frontal plane during single limb exercises this is what you will get when the athlete returns to sport.

Next week we will continue this discussion on single limb training and why that is such a critical part for restoration of proper movement and maximizing carry over to sport.  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. 





Monday, December 24, 2018

Improving Movement When It Matters - Part III

Since the start of this series, we have been talking about the psychology of movement.  Whether it is the fear of movement "Kinesiophobia" or the how we might impact Sport Locus of Control, psychology plays a key role in restoring an athlete's confidence in their movement and trust in their affected limb.  In addition to what we can do psychologically both from a verbal and non-verbal aspect for the athlete, there are also things that our training can do that will help in minimizing or eliminating kinesiophobia and build overall confidence.  Things that we can do in training that will have a huge impact on the athlete's psychology throughout the process and going forward to returning to sport.

In most cases, Kinesiophobia and confidence are intertwined.  Knowing this, there are things we can do from training perspective that will have a huge impact on both confidence and kinesiophobia.  First and foremost is single limb training.  Before we get into the training aspects, let's first look at some facts about single limb training.


  1. Weakness and fatigue in in single limb training adds to increased risk of injury - Brazen et al Clin J Sport Med 2010 showed that SL fatigue resulted in increase in ground reaction forces and peak valgus angles which is correlated to injury risk.
  2. Single limb performance is the best indicator of risk - Myer et al Am J Sports Med 2012 showed that single leg hop is a better predictor of how one will move in sport and therefore be a better predictor of risk.
  3. Single limb performance is a better indicator of athletic performance - Kristinaslund et al Am J Sports Med 2013 showed that single limb performance was a better indicator of athletic performance than bilateral testing. 
  4. Movement in the frontal plane during single limb performance is a good indicator of risk - Stearns et al Am J Sports Med 2014 showed the magnitude of motion in the frontal plane during single limb performance is directly correlated to risk. 
  5. The variance in strength and motion between the right and left leg (limb symmetry index) in single limb performance is a good indicator of risk - Rohman et al Am J Sports Med 2015 showed if there is a >15% variance in closed kinetic chain strength or movement in single limb performance there is an increased risk.
Considering this current literature and some common sense approach to training, it would make sense then that the earlier we start single limb training the better the athlete will do.  Why is this?

  1. Early initiation of single limb training starts to build confidence.  Something as simple as weight shifts or single leg stance starts to build the athletes confidence in the affected limb. 
  2. Early initiation of single limb training starts to build strength in closed kinetic chain.  According to the studies above, single limb performance is associated with risk and more indicative how one will participate in sport.  Closed kinetic chain strengthening (single leg squats) vs. open kinetic chain strengthening (leg extension) has much more carry over to sport. 
  3. Single limb training builds whole kinetic chain sequencing.  The quads, hamstrings, etc rarely function in sport in isolation.  Normally the core, upper thoracic spine, gluts, and lower limb are all active during athletic activity.  Training in upright single limb activities creates motor unit recruitment and muscle sequencing that is more associated with sports participation than open kinetic chain or activities on a table. 
  4. Single limb training limits compensations associated with bilateral training.  When only training bilateral closed kinetic chain activities (like squats vs. single leg squats) one can hide compensations.  Squatting motions with a lateral shift can change recruitment patterns by up to 45% in the limb that is being shifted away from and this may further decrease limb symmetry index. 
As basic as this sounds, the sad part is that it is not the standard of practice in rehabilitation or in sports medicine.  Even today, athletes are progressing to 8-12 weeks post operatively and still not doing any level of appropriate single leg training.  The negative impact consequence is a lack of whole kinetic chain strength development, whole kinetic chain sequencing and building of the athlete's confidence to enable them to return confidently and safely to sport.  Next week we will discuss some parameters for progressing single limb training.  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

Thank you all for following our post, we are extremely grateful for your support.  From my family to yours, we wish you and yours a very Merry Christmas.

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. 

Monday, December 17, 2018

Improving Movement When It Matters - Part II

Last week we talked about Kinesiophobia or the fear of moving.  This week we are going to continue along that line of discussion to talk about your impact on psychological movement. 

Recently I had the honor and pleasure of co-chairing the National Sports Medicine Conference with Dr. James Andrews and Kevin Wilk, PT, FAPTA.  During this conference, Dr. Andrews did a Keynote Speech entitled "My Life In Sports Medicine & The Quest For Excellence In Your Career".  This was a chance for physical therapists and athletic trainers to hear from one of the best about what he has learned throughout his career and what we can take away from that.  One of the things he mentioned is that sports medicine is hard work!  You have to keep up on the literature, be continuously learning and work hard to get to the top or be the best.  He also talked about "don't ever underestimate the impact that you have on the physical and psychological impact of the patient".  This is most evident in those patients who suffer an ACL injury and are on the long hard road of recovery and return to sport.

Ardern et al AJSM 2013 studied the psychological factors that impact an athlete's ability to return to sport.  In this study they talked about two things that can greatly impact an athletes ability to return to sport is fear of reinjury and sport locus of control.  We have talked about Kinesiophobia or fear of movement which plays into the fear of re-injury but does not encapsulate the totality of fear of reinjury (which we will talk about shortly). 



Fear
As with Kinesiophobia, fear of re-injury is addressed in some similar ways.  There are things we can do in rehab that will reduce the fear of re-injury and which should start day 1.

  • Education - fear during rehabilitation comes from uncertainty and lack of confidence which can be eliminated with education. 
    • Educate the athlete about the surgery, the graft and healing process of, what the stages of rehabilitation will be and what the steps will be for returning them to sport. 
    • Educate them on movement and how controlling the movement will help in reducing risk of re-injury. 
    • Educate them on the importance of single limb training and control of frontal plane motion during single limb training
    • Educate them on their role in the rehabilitation process
*Providing this education also has a multiple effect on fear.  By you providing this education, this builds the athlete's confidence in you as their provider.  The athlete having confidence in you as their provider will give them more confidence when you move them through the phases of rehab and progress them to single limb activity as well as more sports specific conditioning types of activities*
  • Early single limb training - starting very early in the process with single limb training.  Even if this is weight shifts to single leg balance with support or single leg press, the sooner single limb activity is started the quicker the asymmetry is addressed and the faster they will build confidence in the limb.
  • Progression to single limb performance training - moving the athlete to more aggressive types of single limb performance training under controlled conditions (in a the clinic or under your guidance) will build confidence.
  • Coach - sometimes taking off your rehabilitation hat and putting on your coaching hat can be difficult for some providers.  But in the later phases of rehab as we move to more aggressive training, the ability to coach an athlete through more difficult training while being mindful of proper movement will help the athlete see what they can really accomplish.
Another psychological factor that can have an impact on movement and an athlete's psychological readiness is sport locus of control.

Sport Locus of Control

Sport locus of control is a psychological term that originated by Julian Rotter in 1954. It considers the tendency of people to believe that control resides internally within them or externally.  In other words, the athlete is in control of their destiny or their destiny is determined by something else.  Throughout an athlete's athletic career, they have been in control of their destiny.  They have come to learn, that they are accountable for their actions and their performance.  If they train hard, put in the time and the effort, then they will perform better and have better results.  They are in control of their athletic destiny.  For an athlete, to have this control is important.

After an injury (especially an ACL injury), many athletes see this as a loss of control.  Their destiny is now in the hands of the surgeon and the surgical technique that was performed.  Their destiny is in the hands of the therapist or athletic trainer and how good they are at ACL rehab.  For the athlete, they have lost complete control of the situation and are now reliant on others for their future destiny.

So this is psychology, can I impact that as an athletic trainer or physical therapist?  You had better believe it!  In the words of Dr. Andrews, "Don't ever underestimate the impact you have on the physical and psychological impact of the patient".  So how do you positively impact Sport Locus of Control and give that control back to the athlete?  All of this starts on DAY 1!

  • Educate the athlete on the injury, anticipated course of rehabilitation and THEIR ROLE in the process.  Let them know their outcome is dependent on what they put into the game, how well they listen to their coach (you) and how well they execute the plays (rehab and home exercises).
  • Coach - coach them through the process.  Encourage them when they need it and yet push them hard when indicated.
  • Empathy not sympathy - be empathetic to your players and have the ability to put yourself in their shoes.  But don't let your empathy turn to sympathy and babying the athlete along the way. 
  • Encourage don't discourage - there will be days to address the psychology of your athlete and step things back a little but also days to push them hard through it in an encouraging manner.  Remember the psychological impact the injury has on them and their life.  Coaching them through that is where champions are made.
  • If your attitude sucks, get out.  Don't ever let your bad day become the athlete's bad day.  We are there to do a job, build people up physically and mentally.  If you let your bad day be reflected in the clinic or athletic training room, it will impact every athlete you touch that day.  DON'T do it.
Next week we will start to look at single limb training and why that is such a critical part for restoration of proper movement and maximizing carry over to sport.  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. 






Monday, December 10, 2018

Improving Movement When It Matters - Part I

Over the course of the last month we have been discussing LSI and what it means.  Although it provides us good information, how do we use this knowledge to create exercises that aid in improving LSI.  The idea is not only to provide the strength and endurance that is needed but also to develop the motor patterns in the higher centers that are needed to and which will aid in having maximal carry over to sport.  If we do that, does that really create movement patterns that will carry over to sport?  This is the golden nugget that everyone is looking for.

Throughout this series we are going to dive into some of the philosophy, physiology, neurology and research behind why we do what we do.  During the course of this series we are going to discuss:

  • Kinesiophobia - what is it and how does this limit return to sport
  • Your impact on psychological movement
  • Why Single limb training aids in maximizing return to sport and athletic performance
  • What is the roll of fatigued state training and why this is important
  • Movement at the hips and how this leads to increased risk and altered performance


Kinesiophobia was first described in the literature in the early 2000s but has recently gotten a resurgence with the publication of some land mark studies.  Kineisiophobia is simply the fear of moving.  In physical therapy, you often see this in patients who have suffered a fall.  They develop a fear of falling and thus a fear of moving because they are afraid of falling.  This results in significant alterations in their gate, moving from piece of furniture to furniture and a shuffling type of gait pattern.  This same fear of movement is also quite prevalent in some athletes following an Anterior Cruciate Ligament Reconstruction.  In the initial phases of rehab they may be fearful of walking with full range of motion (so may end up limiting their terminal knee extension), may be afraid of walking without a brace on or putting weight on their involved leg. 

As we progress through the phases of rehab, this can become more profound and psychologically impactful.  Hartigan et al JOSPT 2013 showed that those with higher levels of Kinesiophobia are not only more likely to have a delayed return to sport but also more likely to reinjure upon their return to sport.  Cozzi et al JSR 2015 showed that those with a higher degree of Kinesiophobia may actually result because of a self perceived level of knee function.  Meaning that the athlete subconsciously knows the function or dysfunction of their knee and sense the risk.  Some studies are now correlating the outcome measures for Kinesiophobia (Tampa Scale of Kinesiophobia) to knee outcome measures (IKDC or Marx Scale) and seeing a strong correlation with.  But, what has yet to be determined is the correlation of Kinesiophobia and movement.  One would suspect that those with significant pathological movement of the knee would have greater kinesiophobia than those who have less.

So what is the treatment for kinesiophobia?  Unfortunately there is not a lot in the literature about how to treat kinesiophobia in the athlete.  There is a fair amount out there about how to treat this in the elderly patient and the low back patient but not in the athlete.  Looking at what literature there is, there is some common themes.
  • Education - educate the athlete about their injury, expected progression of rehabilitation and how importance of restoration of early function
  • Graded exposure to therapy techniques to increase confidence
  • Graded exposure to activity
Although this relates to the elderly patient and low back patient, it also has a lot of application to our athletes.
  • Educate the athlete on their injury, the importance of progression of rehab, importance of incorporating single limb activities early in the rehab process, their role in the rehabilitation process and how this aids in faster/safer return to sport
  • Early introduction to single limb activities.  Myers et al AJSM 2012 showed that single limb testing is one of the best indicators of risk with return to sport.  As such, the earlier single limb training is incorporated into rehabilitation the more confidence the athlete will have in that limbs performance over time
  • Incorporating aggressive single limb training in later phases of rehabilitation.  Kristineslund et al AJSM 2013 showed that single limb performance is a better indicator of how the limb will function in sport.  Considering, this should indicate the importance of pushing more aggressive types of single limb training.  Not only does this help from a strength and endurance perspective but will also improve the athlete's confidence in that limb with sport related activity.

It goes with out saying, this is a criterion based methodology.  All too often I see athletes training (many times under the supervision of a therapist) single limb exercises with dysfunctional or pathological movements.  Remember, the movement that you train is the movement you will get on the field.  If you train bad movement, you can't expect the athlete to have good movement on the field.  So what is meant by criterion based methodology is that the athlete is only progressed once they are able to do the previous level of single limb exercise with proper form.  If they are unable to perform without maintaining good position of the knee and hips, then they should not be progressed up to the next level.

Taking this approach is the first step in building the athlete's confidence in their limb, decreases their kinesiophobia and improves their chances with return to sport.

Next week will continue along a similar line of discussion with talking about your impact on psychological movement.  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. 

Monday, December 3, 2018

Limb Symmetry Index - What is it and Is it important - part VI


Over the course of the last month and half, we have spent a lot of time looking at the research as it relates to limb symmetry index.  For those of us dealing with athletes, rehabilitation of athletes and especially those of us who are attempting to make more informed decisions for return to play, LSI is often something we must consider.  Throughout the course of this series and after reviewing numerous research articles, it appears this topic is not as clear cut as we would like. 

However, based on the literature, there are some key take homes that we should consider:


  1. What % LSI should your involved be of your uninvolved in order to be considered not at risk or for making return to play decisions?  Based on what we have seen, this answer is not clear but 90% seems to be consensus from the field as well as what most of the researchers are aiming for.
  2. How should we measure LSI? Based on the literature, there is a very compelling argument to compare the involved limb to the baseline data for the uninvolved limb (measurement taken prior to the injury or prior to surgery on the uninvolved side).  
  3. What test should we be using? Every study we looked at looked used different battery of tests.  However, one thing is clear, single limb closed kinetic chain testing is what we should be looking at.  
  4. Is the use of a battery of tests better? Based on what we have seen, the more tests you add in your battery of tests, the less likely your athlete is to pass. 
  5. Does equal LSI tell us anything about risk?  The studies are pretty clear that 100% of LSI does not equate to risk.  You can have 100% of bad movement and still be symmetrical.
  6. What should we be looking for when assessing?  The studies are clear, control of frontal plane motion (magnitude and speed) in single limb performance.

So despite creating a lot of questions, we did get some guidance on some aspects.  Part of the
challenge with getting answers to LSI is historically, we have relied on open kinetic chain testing.  Use of the biodex or similar device to get hamstring to quadriceps ratios right to left, strength, torque, etc.  It was this kind of information that helps guide us on LSI and whether or not the athlete was ready to return to play.  However, we would all agree that sitting in a machine and performing an activity in an open kinetic chain provides very different information than what is provided in a closed kinetic chain.  As we all know, as soon as the feet come into contact with the ground and we are upright, there is a different level of core activation, lower kinetic chain muscle recruitment and changes in length tension relationships.  In other words, they are more in sport like positions.

With closed kinetic chain testing comes the challenge of how do we quantify control of frontal plane motion?  My interpretation may be different than yours which is different than the next person.  However, with the advent of new technologies, there are now ways to quantify these motions in meaningful ways.  What we know, is that we need to assess control of frontal plane motion and that means control of the magnitude of motion and the speed of motion.  Why both?

This comes down to basic physics.  First, the ACL is about the size of your pinky.  The ACL is ruptured with 21.5 N/M of torque (rotational component).  If you look at the calculation of torque, what you get is Ƭ=𝐼ά – inertia *angular acceleration.  The ACL is also ruptured with 250 kg force.  If you look at the calculation of force, what you get is F = mass * acceleration (Hewitt et al Mayo ACL Consortium 2018 - reference for values not calculations).  In addition, force is determined by both the magnitude of the force vector and the speed of that force vector.  The larger the magnitude the greater the force.  If the magnitude is the same but one occurs at a faster rate, this will generate more force.  Considering these physics, it then makes sense that we should be measuring not only how much frontal plane motion that occurs but also the speed at which it occurs. 

As we have mentioned in previous blogs, we have been capturing this with a wearable sensor or IMU (inertial measurement unit, DorsaVi Inc.).  During the test, the athletes perform series of core tests, squat test and single limb tests for a total of 83 reps and 3 one minute timed tests.  The system captures 2D video at 90 frames per second and the sensors captures 3D motion at 200 frames per second.  Each rep is scored based off those motions.  This is a commercial product that has been released to the market since early 2017 (DorsaVi ViPerform AMI) and has now been used in over 269 athletic settings throughout the US.  With the use of the IMU, we are now collecting over 1000 data points for every assessment that is performed.  As a result number of sites using, it has allowed us to capture movement on over 9000 athletes across the US.  With this large mass of data points collected, it has raised one major question.  What is passing score?  Not sure if we know this answer yet.  Let me explain.

If we were only looking at 16 year old female soccer players, we might have a better idea.  But, when you collect across all athletic populations, from high school to professional your data pool to compare mass numbers of a subset population is hard.  What happens when you compare a 16 year old female soccer player to a college lacrosse player to a professional football player to professional MMA fighter?  Should these athletes move the same?  What I can tell you is that there is a HUGE difference in the way a Division I Soccer Player, a Division II Soccer Player and Division III Soccer player moves.  It is one of the things that separates a division I player from a division III player.  Not only do they have better frontal plane control during single limb activities there is significantly less losses of balance during. 

At the same time, we also know that athletes in the same sport but in different positions move very differently.  For example, if a 330# professional football player lineman falls into 15 degrees of valgus at 180 degrees/sec during a hop plant test he may not be at risk where  220# running back with those same motions and speeds may be.  This makes a lot of sense when you consider the amount of running one player does compared to another.  In addition the running back has more cutting and rapid changes in direction resulting in much greater center of mass displacement during single limb movements than the lineman.

So this might lead us to the question, if you don't know what the passing score is then what does the data mean?  What we are able to do is determine LSI in both magnitude of motion and speed of motion.  We do have some normative data for frontal plane motion and speeds of valgus during a single leg squat, single leg hop and single leg hop plant.  We know if you are significantly out of those ranges that you are at greater risk that it will impact your injury risk and your athletic performance.  We also know that if your valgus speeds exceed 200 degrees per second that this has a high correlation to increased risk for non-contact hamstring strains, knee injuries and ankle injuries.  Most of our teams and users do baseline tests so they can use this information to compare to following injury or post intervention.  So the point of this whole discussion is that we are trying to use what the literature tells us we should be looking at and at the same time, using our real time data to drive how we interpret and use this information. 

Stay tuned next week as we start to look at fatigue and impact this has on SL testing and return to play.  If you enjoy this blog, please share with your colleagues and associates.  You can also follow us on Instagram at bjjpt_acl_guy and on twitter at ACL_prevention.  #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 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.