Monday, September 26, 2016

Should We Re-Think How We Look At Movement

Throughout the course of the last several series of blogs, we have discussed a lot of the research around biomechanical risk factors, fatigue and how this should weight in our decisions when considering how to assess and treat movement.  On 9/12/16, we posted a somewhat controversial blog looking at the latest research on the Functional Movement Screen or FMS.  Although the FMS is an excellent tool for screening movement asymmetry and movement overall, what the research indicates is that it might not be that great at identifying movements that put athletes at risk.

So, considering what we have talked about and literature that we have reviewed over the course of the last several months, what should we consider when looking at risk factors for non-contact ACL injuries?  This is the question that everyone is striving to figure out.  As we all know, the non-contact ACL injury is a very complex problem and according to the literature, involves a plethora of factors that should be considered.  All too often, we think of movement as the only risk factor.  However, according to the literature, this is only part of the picture.  As a clinician, this is one of the most frustrating things about research.  So many great researchers are producing ground breaking evidence but yet they all appear to work in their own separate silos.  It appears that none of them bring together the body of literature to provide a more comprehensive approach.  To truly have a comprehensive look at risk, should we not include known demographic risk factors as well as movement risk factors.  Clinically we take the athlete's or clients history and our clinical exam to determine the root cause and from that we develop an intervention.  In research the clinical decision making process is all done in isolation and the findings are not leveraged to drive the intervention.  Understanding there are a lot of variables you need to control in research but end of the day, does this drive a comprehensive approach? 

 
Part of the restriction including all the "known" risk factors is that there is not a way to do this efficiently.  End of the day, in order to have a dramatic impact on non-contact injuries, we need to have an efficient way of implementing the body of research.  If it is not efficient, adoption will not happen and therefore our impact will be minimal.  If implemented all that we know today as risk factors using traditional methods, this would take 40 min to an hour per player.  For any of us that have done physicals, we know that is not possible.  So no matter how good your intervention is, if it is not efficient it will not be adopted.  Whatever we do must be efficient. 

On the flip side, there is a large movement to come down to 1-2 movements that identify risk.  This would address the efficiency factor but is that the answer?  We know clinically in order to assess an overhead athlete for a possible labral tear that we have to take into account the athlete's history, symptoms, and perform several provocative tests.  Could you do one provocative test?  Yes.  But, is your sensitivity and validity of your diagnosis of the root cause better when you consider all these factors and do several provocative tests?  Definitely.  However, looking at one or two movements might identify risk and may help to reduce risk by 40%.  But, is 40% good enough.  Are we satisfied with 40%.  If my child or athlete falls in that 60%, then no, that is not good enough. 

So, how do we do it better?  We do it better by combining all the known risk factors.  Until the advent of current technologies, we have not been able to do that efficiently.  With time of flight technologies and IMUs, we are starting to see ways in which we can do this.  A time-of-flight camera (ToF camera) is a range imaging camera system that resolves distance based on the known speed of light, measuring the time-of-flight of a light signal between the camera and the subject for each point of the image.  This is the type of technology that the Microsoft Kinect and other similar devices function off of.  An inertial measurement unit (IMU) is an electronic device that measures and reports a body's specific force, angular rate, and sometimes the magnetic field surrounding the body, using a combination of accelerometers and gyroscopes, sometimes also magnetometers.  This is the type of technology used by DorsaVi, Myomotion, BPM Pro and others.  Now that we have technologies that allow us to integrate all these factors, what should we consider in order to get a comprehensive view of risk.

So, if we have technologies to do this and in order to develop this comprehensive look at risk, the question becomes, what factors we should consider and which ones can measure or influence.  Approaching this from a physical therapy, athletic training or performance coaches perspective, there are factors that we can measure but we may not be able to do it efficiently, cost effectively as we need or influence once they become known.  For example, in 2006 Griffen et al looked at all the known risk factors.  Although we know that femoral notch depth and menstrual cycle influence risk, can we efficiently, cost effectively and reliably measure that clinically without the use of expensive equipment and time consuming procedures?  Approaching this from the clinical perspective, one should think about what factors would you consider in your typical history with an athlete or patient.  For that, we can look to the literature.

Based on the literature, some factors that should be considered from the history or demographics include:
So, we know these are the demographic risk factors.  But for us to have a truly comprehensive approach, shouldn't we combine this with known movement risk factors?  So in addition to the demographic factors, we also know there are things we should look at from a movement perspective.  These include:

One would think that if we combine only one or two of these factors and we can reduce injury rates by 40%, that if we combined all the known risk factors that the sum impact would be much greater than 40%.  Obviously, this depends on the intervention.  Next week we will discuss how we apply this to our interventions.

Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >3000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training. 

Monday, September 19, 2016

Improving Movement When It Matters - Part IVE

Over the last month and a half, we have been looking at the impact that fatigue has on movement.  During the course of these "fatigue related blogs" we have highlighted the research associated with and also evaluated how we can use this knowledge to improve the movement assessments that we perform.  A couple of weeks ago, we highlighted some research we have been doing with Division I and II athletes and how we have included this concept of pre-fatigue into our movement assessment pre-participation physicals. 

The reality is, we came across this by circumstance.  We started our data collection on Division I and II athletes and were ~4 days into the data collection.  At this point, we had moved on from the Division II athletes to the Division I athletes.  To our surprise, we were not seeing the level of movement dysfunction that we hypothesized we would see.  This is to be expected due to the heightened level of athleticism, level of fitness and length of time at a higher level of play.  That said, our Division I athletes were still encountering a lot of non-contact lower kinetic chain injuries that we hypothesized we could assess contributing factors.  But, for the majority, we were just not seeing a lot.  However, the last 2 athletes to be tested on the last day came in and during their assessment, their movement was remarkably worse than the rest of their teammates.  These same two athletes also were reported as the two best on the team, which you might suspect would then translate to moving better.  Both of the players were exhausted at the conclusion of the testing which prompted us to inquire about why the level of fatigue.

To our surprise, both of these athletes had participated in a field agility test just prior to our testing.  This was an agility test the coach would put them through to fatigue them out so he could see what he had to work on with them from a performance standpoint.  This was the defining event that resulted in us forever changing the way we looked at our athletes.  From that point on, we started to dig into the fatigue literature and see how we could use this as a part of our assessment.  As time went on, we also started to question the way that we provided our intervention.

Conceptually, physiologically and neurologically, it would make sense that if we applied this concept of fatigue to our training that the carry over would be much better.  Considering the concept of specificity, in order for the training induced responses to have the maximal carry over to the activity for which you are training that it should be as specific to that activity as possible.  So what does that mean?

Simply, to improve how an athlete moves later in the game, when they are fatigued, wouldn't we
want to train them in a fatigued state?  After the implementation of fatigue state testing, we then started to evaluate this concept of fatigued state training in 2009 and had seen some significant impacts on injury rates in addition to compliance with the program.

In 2015 in the American Journal of Sports Medicine, Soomro et al performed a meta-analysis of 9 randomized controlled trials across 10 different published studies.  What the authors found was that injury prevention programs (IPPs) that were the most effective at reducing injury rate ratios (IRR) were those that addressed muscular strength, proprioceptive balance and flexibility.  Further, the authors found that programs that included more of these key factors (versus just one or two) were more effective.  In addition, programs that were 20 minutes or less in duration tended to have better compliance and ones that used post practice training (fatigue state training) had larger reductions in IRRs.

For us, this just confirmed we were on the right track.  So the program that we developed has a pre-practice warm up and a post practice routine that takes less than 20 minutes to perform.  The post practice routine (Fatigued State Training) utilizes the fatigue that is created in practice and carries that over into the training routine.  In addition, training in this manner allows us to be much more efficient and reduce our volume of training so that we can have just as significant an impact with few reps and sets.  Most importantly, it trains athletes in a fatigued state so when they are fatigued, they move better, reduce their injury risk and improve athletic performance.

Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >3000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training. 

Monday, September 12, 2016

Improving Movement When It Matters - Part IVD

Last week, we looked at the results that you can have when you integrate fatigue into a movement assessment.  Specifically, we looked at what happens when you perform a standardized fatigue protocol prior to the initiation of a movement assessment and how this can impact what you see in your athletes.  But what if we took this a step further and integrated this same philosophy into the design of our movement assessment?

When thinking about movement assessments in athletics, one that jumps to the top of mind is the Functional Movement Screen or the FMS.  This is the most widely used and recognized movement assessment on the market.  The FMS, as they define, is the screening tool used to identify limitations or asymmetries in seven fundamental movement patterns that are key to functional movement quality.  Before getting into our discussion, we should say that nothing in life is perfect.  In order for continuous improvement, we must recognize limitations of whatever tool it is that we use and constantly strive to improve upon. 

In this authors mind, the FMS transformed the way we looked at movement in athletics and created an awareness for movement.  For that fact alone, the FMS should be recognized as a transformational approach that it has been and is.  Although the FMS will state that it is a screen, it is more often used in athletics as a tool to assess if an athlete is at risk for injury.  That said, there are some fundamental flaws with using it in this manner and the research is beginning to question it's validity as a tool for prediction of injury risk. 

In June 2011, Bardenett et al looked to determine if the FMS is a valid predictor of injury in high school athletes.  In this study, the authors used the FMS to assess 167 high school athletes and monitored them during a single season.  What the authors found was there was no statistical significant associations between the total FMS score and the injury status.  Although the FMS was useful to recognize deficiencies in the "movement patterns tested" the data suggest the FMS should not be used for overall prediction of injury in high school athletes.  In other words, the FMS was good at identifying asymmetry in the movements tested but makes us question if the movements tested are truly associated with risk.

In October 2015, Dorrel et al performed a systematic review and meta-analysis of the research in this area to evaluate the FMS as an injury prediction tool among active adult populations.  In this meta-analysis the authors reviewed 7 studies from 1998 to February 2014.  What the authors found was the FMS was more specific (85.7%) than sensitive (24.7%), with a positive predicative value of 42.8% and a negative predicative value of 72.5%.  In other words, this test predicted injury correctly 42.8% of the time and predicted it incorrectly 72.5% of the time.  Based on the analysis, the authors suggest the findings do not support the predicative validity of the FMS.

Finally, in February 2016, Bushman et al looked to determine the association of the FMS with injury risk, assess predictive values and identify optimal cut points.  In this study, the authors used 2476 physically active male soldiers age 18 to 57.  The authors performed the FMS on all the soldiers and then tracked all of them for a period of 6 months for overuse injuries, traumatic injuries and any injury during that period of time.  What the authors found was although poor FMS performance was associated with higher risk of injury, the test displayed low sensitivity and low positive predictive value.  As a result of these findings, the authors recommend that the FMS not be used in this population due to the low predictive value and the misclassification of soldiers injury risk.

All of these studies, as well as more, highlight some flaws when trying to use the FMS as a injury prediction tool.  One area that keeps coming up in the studies is the area of sensitivity and predictive value.  Part of what makes a battery of test more sensitive and predictive is that it is measuring what it is intended to measure (risk) and that the scoring methodology is able to detect change (improvement or regression).  The FMS is challenged with this in couple of ways.

  • The movements themselves are not associated with the biomechanical literature.  As cited in our previous blog, risk is associated with several factors including single limb performance (single leg squat, single leg hop to name a few), magnitude of valgus at the knee and speed at which valgus occurs.  This test does not measure that or at least in a way that is reflected in the literature.
  • The overall score of this battery of test is based on 21 points.  Therefore, a subject could improve on all the reps in a single test with the exception of 1 and this would not be reflected in the score.
Now, back where we started in our discussion of fatigue.  When we consider the concept of fatigue and the impact this has on risk, does this test incorporate that?  Does the 3 reps that are performed on each individual test really representative of what an athlete looks like on the field when it matters the most?  Isn't it toward the later half of the game where we really start to see movement deficits become apparent and where performance is impacted the most?  Should we not take that into consideration when we perform our movement assessments?  Should we include more repetitive single limb testing over multiple repetitions to see how the athlete truly moves?   If we truly challenged the core (over multiple tests and longer periods of time) wouldn't this give us a better idea of the athlete's ability to sustain stability when it counts?  Should we include these considerations, the impact of fatigue and combine this with what the research tells us we should test?  If we did this, could we have a better impact on injury rates and athletic performance?

We are starting to see the answers to these questions being evaluated.  With the advancements in technology, this could also drive improved efficiency and sensitivity of movement assessments especially when performed as a part of mass physicals.  Aside from movement assessment, how should these same concepts be applied to our interventions?  That is a question we will look more into in the coming blog.

Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >3000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training. 




Monday, September 5, 2016

Improving Movement When It Matters - Part IVC

Over the last couple of weeks, we have been looking at the impact that fatigue has on human movement.  We know from the literature that athletes are at greater risk of injury later in the game.  This is due to the impact that fatigue has on response time, muscular strength and proprioception to name a few.  As such, assessing fatigued state movement should be a standard of practice however, few, if any, movement assessments incorporate this concept.

It is one thing to consider this conceptually, but another to put this in practice.  If you were to put this in practice, what kind of results can you get?  Although there is not much in the literature on, what we know through our own research is this can have a huge impact on your outcomes.  This is one of the things we have been evaluating for the last 8+ years.  Although our research is not published, all of it is IRB approved and is developed under the process of "Proper Discovery".  This simply means that in each study, we take what we learn and apply that for process improvement and re-evaluate what kind of impact this has.  It is the purest form of applying research to clinical practice and is what we do every day in the clinic.

Before discussing what we see, we should reiterate with this level of testing there are some clear guidelines that should be followed.  Prior to implementation with post op patients, the following should be met:
  1. >24 weeks post op if ACL
  2. Full pain free ROM
  3. <1+ effusion with stroke test
  4. >70% symmetrical quad strength
  5. Cleared for plyometrics
  6. Cleared for lateral/diagonal movement
This type of testing is also contraindicated and requires medical clearance with those with a history of:
  1. Cardiac History
  2. Arrhythmia
  3. High blood pressure
  4. Asthma
  5. Sickle Cell Anemia
In our study with Division I & II female soccer players, we performed movement assessments on 102 players under 2 separate conditions.  Athletes were then categorized, based on their overall scores as:
  1. Low risk
  2. Minimal risk
  3. Moderate risk
  4. High risk
Based on the risk rating, athletes were then assigned to one of four intervention groups.  Level I for those at high risk and level IV for those at low risk.  The team then performed these exercises all season long.  Throughout the season, we tracked injury rates, days on the DL, average days on the DL and health care claim submissions.

Scenario I: All athletes performed a movement assessment consisting of:
  1. Full squat test
  2. Step up test
  3. Single leg squat test
  4. Single leg hop test
  5. Plank test
  6. Bilateral side plank test
Each athlete was scored on each test and based on their overall score provided a risk rating.

Scenario II: All athletes performed the functional agility short term fatigue protocol (FAST-FP) and then performed the movement assessment as described above.  Each athlete was scored on each test and based on their overall score provided a risk rating.

When looking at the data, this is what we found:
  • Non-fatigued state
    • Average RPE 6/10
    • 25% of athletes categorized as "at risk"
    • 2% of the athletes categorized as "high risk"
    • Average score on core was 7.5 for all subjects
  • Fatigued state
    • Average RPE 8.5/10
    • 5% of athletes categorized as "at risk"
    • 36% of athletes categorized as "high risk"
    • Average score on core was 4.5 for all subjects
Although there is still a lot of questions about the data and some variables that were not controlled or assessed, athletes in this study were assigned to the intervention group based on their fatigue state data.  For our intervention group (N=42), we had the following results:
  • 100% reduction of non-contact ACL injuries Y1&Y2
  • 60% reduction in the number of days on the DL
  • 58.2% reduction in the number of non-contact LKC injuries (foot, ankle, knee, hip and low back)
  • $200K reduction in claim submissions over a 2 year period

Keeping in mind this was only an N=42, the reduction in ACL injuries is not statistically significant.  But the number of days on the DL, the overall reduction rate in LKC injuries and the cost savings is.  From a research perspective, we should have compared intervention based on fatigued data and non-fatigued data.  However, based on the fatigue state data and wanting to do the best thing for our athletes, we chose to only do based on fatigued state data.  Although this is a criticism from a research perspective, from a clinical perspective it was the right thing to do and in the end, helped a lot of kids.

Next week, we will discuss how we apply this concept of fatigue to our movement assessment in the absence of a pre-fatigue protocol.

Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >3000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training. 




Monday, August 29, 2016

Improving Movement When It Matters - Part IVB

Last week, we reviewed some of the literature as it relates to fatigue.  The take home from all this was the question, should we include this philosophy in our assessment and in our training.  As a review and from the previously reported studies, we know that fatigue:
  1. Decreases force attenuation
  2. Increases shear stresses at the knee by
    1. Increasing valgus stresses
    2. Increasing tibial rotational stresses
    3. Increasing foot pronation
    4. Increasing facet pressures
  3. There is a larger impact in female athletes than male athletes
Considering the above, what we should take away from this is that we should include some form of fatigue methodology into our movement assessment.  When considering this, there is really two ways to go about this. 
  1. A standardized fatigue protocol prior to movement assessment
  2. Employ a movement assessment that brings in a fatigue component
When considering a fatigue protocol, we should look to the literature to guide us on what we should use.  To do a fatigue protocol, it must be efficient, cost effective and something you could do in the clinic without the need of purchasing expensive equipment.  in 2012, in the J of Athl Train, Quammen et al looked at two different fatigue protocols, the SLOW-FP and the FAST-FP (slow linear oxidative fatigue protocol and the functional agility short term fatigue protocol).  The SLOW-FP is the one we traditionally think of that is a treadmill based protocol and the FAST-FP we will describe shortly.  The authors had 15 female soccer players perform both protocols and looked at kinematic and kinetic measures taken via Viacom.  The measures for both protocols were compared to pre-fatigued state measures.  What the authors found was that the FAST-FP had a greater impact on kinematic and kinetic measures known to put athletes at risk. 

The take home from this was that by implementing the FAST-FP, we now have an efficient, cost effective protocol that can be implemented in the clinic as a part of a movement assessment designed to assess an athletes movement in a fatigued state. What we have found is that use of the FAST-FP prior to testing will often reveal movement patterns that were previously not seen in our higher end athletes.  To perform the FAST-FP, all you need is three cones, a 31 cm step and agility ladder.  The athlete performs the FAST-FP in the following sequence:

  1. 31 cm step up for 30 seconds at 220 bts/min
  2. L drill (Pictured here)
  3. 5 counter jumps at 80% max
  4. 5 yard agility latter
    1. Set 1&3 in forward direction
    2. Set 2&4 in lateral direction
Each of the exercises in this sequence is performed immediately after the other with the athlete jogging from one to the next.  The entire sequence takes a total of 4 1/2 to 5 minutes.  Immediately after this fatigue protocol, the athlete then moves into the movement assessment so that the fatigue that is created in the FAST-FP is carried over into the movement assessment.  This is a very aggressive form of testing and we only recommend performing this type of assessment with your higher end Division I athletes and above. 

With this level of testing there are some clear guidelines that should be followed.  Prior to implementation with post op patients, the following should be met:
  1. >24 weeks post op if ACL
  2. Full pain free ROM
  3. <1+ effusion with stroke test
  4. >70% symmetrical quad strength
  5. Cleared for plyometrics
  6. Cleared for lateral/diagonal movement
In addition, contraindications to this level of testing (unless medically cleared) are:
  1. Cardiac history
  2. Cardiac arrhythmia
  3. High blood pressure
  4. Asthma
  5. Sickle Cell Anemia
 Finally, during this level of testing, you should be following the athletes ratings of perceived exertion.  Most athletes (high level) will find this an 8/10 on this scale.  Our elite (Olympic) to pro-athletes typically rate this 7/10 on this scale. 

In absence of the FAST-FP, is there a way to include this philosophy in our movement assessment.  Next week, we will continue this discussion as we look at that question in more detail.

Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >3000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training. 

Monday, August 22, 2016

Improving Movement When It Matters - Part IV

Over the course of the last couple of weeks, we have been looking at the impact of single limb performance and the importance this has to overall carry over to sport and overall injury risk reduction.  For many of us, it is also intuitive the impact that fatigue has on overall risk.  We know from antidotal data, for example, that injuries tend to occur in our players later in the game or day when the athlete is fatigued and not able to respond as quickly.  Despite this fact, very few appear to consider this or apply this when developing both assessments and intervention.

Since the late 80s, there has been over 2000 papers published in the literature outlining the impact that fatigue has on the movement.  As late as 1986, Skinner et al in  J Ortho Research showed that fatigue had an impact on joint position sense of the knee.  In 1999, Rozzi et al J Athl Training showed the effect of muscular fatigue on neuromuscular characteristics in the male and female athlete.  In 2012, Cortes et al J Athl Train showed that a short term fatigue protocol had not only an impact on frontal plane motion but also peak adduction moments expressed at the knee.  Considering, this, we want to take a look at a couple of key studies.

In 2005, Chappell et al Am J Sport Med looked at pathokinematics in a rested state and in a fatigued state on a jump stop in 20 recreational athletes.  First, each athlete performed a jump stop jumping forward, vertical and backward while measuring knee joint angles and ground reaction forces.  This was followed by each athlete then performing a fatigue protocol which consisted of 5 vertical jumps, a 30 yard sprint, 5 more vertical jumps and another 30 yard sprint.  Athletes were then measured again for the same three jump stop testing conditions.  What the authors found was that in a fatigued state, the athletes demonstrated an increase in proximal vertical shear, increase valgus and a decrease in knee flexion (resulting in increased ground reaction forces).  The take home from this is that when our athletes are fatigued, these same stresses will increase at the same time when the athlete is also not attenuating force across the system in an optimal way.  Both of these conditions not only add to an increase in risk for injury but also impact athletic performance. 

Kernozek et al in Am J Sport Med further demonstrated this fact in 2008, showing the impact that fatigue had on increased shear at the knee and decrease in force attenuation.  The fact that there is both an increase in shear and forces distributed to the knee should give us pause!  It should make us wonder if we are not including fatigue as a part of our movement assessment, are we truly getting the full picture of what the athlete looks like or what their risk is.  How can we possibly, if we are not assessing it?

According to  the previously cited studies, we are getting an idea of the impact that fatigue has on knee risk.  But, is this isolated to just the knee?  If we look at the Weist et al study of 2004 in the Am J Sport Med, we see that fatigue impacts more than just the knee.  In this study, the authors looked at the impact fatigue has on the plantar pressure patterns in the foot. The authors evaluated EMG activity of 14 muscles pre and post fatigue in addition to evaluating plantar pressures during a run in 30 experienced runners.  Each runner was put through a maximal exhaustive run and fatigue was measured via blood lactate.  What the authors found was that there was an increase in MT pressures with fatigue.  The authors further concluded that the muscles that had the most significant change in MVC were the G.med, G.max and Med/lateral gastroc, in that order.  The take home from this is that fatigue of the hip musculature results in increased MT plantar pressures.  So, this should make us all question:

  1. If our movement assessment does not take the athlete into some level of fatigue, are we truly getting an true representation of what they look like in a fatigued state?
  2. If our training does not push fatigued state training, is the carry over to sport and fatigued states the best that it could be?
Next week, we will continue this discussion as we look at adding fatigue testing to our movement assessments.

Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >3000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training. 

Monday, August 15, 2016

Improving Movement When It Matters - Part IIIE


Last week we continued our discussion about the importance of single limb training and how frontal plane motion of the knee in the absence of excessive pronation and excessive pelvic motion may be more associated with weakness in the hip complex.  This week, we will conclude this discussion on single limb training by looking at the hip. 

Keeping in mind, the intent of this entire discussion is criterion based progression.  The criteria for progressing single limb training from one level to another is the fact that the athlete is able to perform the previous level while demonstrating good technique and control at the foot/ankle, knee and hip.  So specifically, what are we looking for at the hip?

Hip
As previously mentioned, sometimes due to our hyper focus on the knee, we forget about the hip/core and to closely asses what motion is occurring at the hip.  Is it the pathological motion at the hip that is driving the frontal plane motion at the knee? 

In single limb training, there are three predictable patterns that athletes fall into. 

Trendelenburg:


This is one of the most common and is easiest to identify by what happens on the contralateral side to the stance limb.  In this case, the athlete is standing on his left leg and his gluteus medius on the left side and the core musculature on his right side (obliques, quadratus laborum, multifidus)  is weak.  The result is that the pelvis drops on the non-stance leg side.  This will often lead to a significant shift of center of mass which leads to a loss of balance.  This is easily observed by the athlete needing to touch the non-stance leg to the floor in order to maintain balance. 


Retro-trendelenburg:

This is one of the most commonly missed compensations that occurs with a weakness in the core and pelvis.  In this position, the gluteus medius is placed in a shortened position which has a significant impact on gluteus medius  and core (obliques, quadratus laborum, multifidus) EMG activity.  Try this!  Stand up.  Place your fingers lightly on your right gluteus medius.  Stand on your right leg and put your left leg back in an athletic position.  Feel the muscle contraction and fasciculations occurring in your right gluteus medius.  Now, move over in the position represented in the accompanying picture.  What happens to what you feel on your glut?  You should feel a significant reduction in muscle contraction or almost completely inactive.  By putting your gluteus medius and core in this shortened position, you significantly reduce the muscles' contractual ability. 

This is really important to identify.  If this is not identified, then the likelihood that this will be missed in single leg training is increased.  If that is the case, then training that is being performed to improve gluteus medius and core strength will be much less effective and the athlete will be progressed to a level that they are not ready or capable of performing properly.  This also means the athlete could potentially be progressed to return to sport with this residual weakness which will put them at risk of re-injury with return to sport.

Cork Screw:

This motion is a combination of both a trendelenburg and rotation at the hip.  This represents more advanced weakness of the gluteus medius and core (obliques, quadratus laborum, multifidus).  During this movement, the associated muscle weakness is significant enough that the muscles are failing through a larger range of the motion that they are biomechanically designed to resist. 

These individuals are at a much higher risk for severe pathology at the hip (hip labral tears) as well as non-contact athletic low back injuries.  In addition to the impact to additional injury potential, this motion also has a significant impact on athletic performance.  The magnitude of kinetic energy loss and loss force production is most evident in the lose of vertical jump and sprint speed.  These athletes will also have a much higher risk for loss of balance.  In jumping sports (basketball and volleyball) this then puts them at greater risk for non-contact ankle injuries.

Two simple exercises that can drive improvement in the hip/core strength is the side plank and plank.

Side Plank



EMG studies of the side plank show significant EMG activity in both the gluteus medius in addition to the obliques and quadratus laborum.  The side plank is performed incorrectly 80% of the time by athletes.  Most of them demonstrate a retro trendelenburg during the movement, rotation of the hips or do not have their hips in line with their feet and shoulders.  Ensuring proper technique with this exercise is critical to maximize the training effect. 

Plank


EMG studies of the plank show significant EMG activity of the multifidus and rectus abdominus when performed correctly.  Again, the plank is performed incorrectly 80% of the time by athletes.  Most of them demonstrate a flexed hip position or increased spinal extension or rotation of the hips.  Ensuring proper technique with this exercise is critical to maximize the training effect. 

Next week we will start our discussion on fatigue state training. 


Dr. Nessler is a practicing physical therapist with over 17 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment.  He is the developer of an athletic biomechanical analysis, is an author of a college textbook on this subject  and has performed >3000 athletic movement assessments.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Chairman of Medical Services for the International Obstacle Racing Federation and associate editor of the International Journal of Athletic Therapy and Training.