Monday, January 27, 2020

The Evolving Knowledge of Movement - Part VIB What We Know Now

This is a continuation of the series we initially started back in December 2019.  We interrupted with my annual plea to make this the year we make change, so I thank you for indulging me in that.   As a refresher, we started Part IV talking about what movement patterns we are seeing associated with concussion.  We discussed some of the impact we are seeing that concussion has on lower kinetic chain movement during single limb testing.  These included:

  • Increase in frontal plane motion at the knee
  • Increase in frontal and transverse motion at the hip
  • Increased time to Stability
  • Increase in loss of Balance 
  • Larger displacement of landings on a scatter plot

Conceptually all of these make a lot of sense when you think of the signs and symptoms we usually see with our concussed athlete.  Although we have not seen the above consensus validated in the the research yet, we do know that athletes with concussion are at greater risk for lower extremity injury (McPherson et al Am J Sports Med 19) and those with a loss of pelvic control (or dynamic stability) are more likely to be concussed (Johnston et al Am J Sport Med 19).  Considering, the above, the measurements we are seeing could be potential mechanism or root cause for the why we are seeing increased risk post concussion.

No matter what your stance is, the evidence is pretty clear that this should now be a part of our concussion protocol or treatment as we get the athlete ready to return to sport.  Based on what we are measuring, we have seen some significant improvements in the above measures when we include the following into our concussion rehab.  With each exercise we will discuss some technical points.  Although this may seem rudimentary I see patients all over the US in high level clinics doing these exercises wrong.  Some simple technique corrections will have a huge impact on the motor plan that is trained and the one they will revert to as their default.

  1. Single limb training - when symptoms allow, the athlete should start single limb training.  Below is a recommended single leg progression along with some technical points to improve the measures we see altered in our concussed athlete.
    • Single leg squat - the athlete should be able to perform 10-20 body weight reps per leg.  The position is the "athletic position" with the contralateral leg off the ground with the knee flexed and in slight extension.  Technical notes include:
      • Control frontal plane motion and speed - they should maintain limited frontal plane motion and speed of valgus of the knee during performance of the exercise.  As noted here, this athlete is not able to do that.  In this case, I would step him back to a stride stance (contralateral leg behind and in contact with floor) and decrease the range of motion to allow him to build the stability there.  From there I would progress to performing without contralateral limb touching.  
      • Control loss of balance - they should not touch the contralateral (opposite) leg down at any time during performance of the recommended reps.  Touching down with the contralateral leg is considered a loss of balance and with an increase in frequency in this comes an increased risk of injury.  In this picture the athlete is touching his foot behind him to create more stability.
      • Control of pelvic motion - all too often when an athlete performs a single leg squat, we let them have excessive movement of the pelvis and trunk (in the frontal and transverse plane).  This will appear as a trendelenburg, retro-trendelenburg or cork screw.  Many times the athlete will get into the habit of doing this as this change in center of mass (or gravity) will create more stability at the hip and allow them to perform the single leg activity.  It is important to correct this and step back the activity to a easier form until they can perform while creating stability of the trunk and pelvis in the frontal and transverse planes.
    • Single leg hop - performing a vertical single leg hop is a great next level of progression.  Due to the increased power demand with takeoff and increase in force attenuation during landing, this is much harder to stabilize than a single leg squat.  The position should again be done in the "athletic position".  Technical notes include:
      • Control frontal plane motion and speed - there will be an increased difficulty creating this stability in single leg hop.  If they are unable to do without excessive frontal plane motion and speed, we can do sets they are able to perform correctly and as they lose control move back to a single leg squatting position.
      • Control loss of balance - as we increase in demands, maintaining stability will be increasingly more difficult.  A lot of times if the athlete is not able to stabilize the pelvis during explosive hops they will loss their balance.  So it is important to determine if this is more result of a proprioceptive issue or loss of control of the pelvis.
      • Control of pelvic motion - this is harder to see in hopping activities.  If you video tape the athlete using a device that is at 90 fps or greater, you should be able to clearly see if they are having excessive pelvic motion.  Lot of times this will happen if they have a lot of quadriceps weakness and inability to generate the power needed.
    • Multidirectional Hops - moving from a straight vertical hop to multidirectional hops takes the athlete to a much more sport specific type of activity.  This can be anterior, posterior, medial, lateral or diagonal.  Of all the directional hops we do, the one that we see athletes have the most difficulty with is the medial hop.  Hopping on one leg in the medial direction (toward midline).  This requires a tremendous amount of strength and endurance at the hip and lower extremity to stop the center of mass from moving medially upon landing all while stabilizing the knee and hip at the same time.  
    • Collision Hops - there is some emerging research coming out of Australia that indicates that a lot of the non-contact injuries that occur in athletics have some form of initial contact with another player in the air.  What happens is that the contact in the air alters where the athlete lands relative to their center of gravity and they try to cut or stop which places excessive stresses on the lower extremity resulting in injury.  Considering this, we can perform perturbations to the athlete in the air during their single leg hops.  This does not take an excessive amount of force but does require then to readjust prior to landing.  
  2. Core training - is has become much more evident that lack of core stability or "dynamic stability" of the core is a factor that is impacted with concussion and when improved reduces the risk of concussion.  DeBlaiser et al Am J Sport Med 2019 showed that impairments in core stability adds to increased risk of lower kinetic chain injuries.  As such, two exercises shown to have the largest influence on core stability are the plank and side planks.  These are the two exercises I see performed incorrectly most of the time.  Some key notes:
    • Sideplank - keep your feet on top of one another and hand on hip.  This prevents from reaching hand forward and rotating the spine.  You should be able to draw a straight line from your between your feet, between your legs along the spine and bisecting the head.  Letting your hips rise of fall or rotate will alter this alignment.  Should also make sure your shin on the down leg is NOT resting on the floor.  This is an indication of ankle weakness and allowing it in training will increase.   Athletes should be able to maintain this position easily for one minute.
    • Plank - feet should be placed all the way together.  Your hips and spine should be in a
      neutral position and your gaze downward but with a neutral cervical position.  Looking up lengthens the anterior structures and places the cervical spine in extension.  Most often, athletes will get the spinal position correct but not the hip position.  The hips will either be up in the air or down.  The idea is to create stability with the hip in a semi-neutral position.  Athletes should be able to maintain this position easily for one minute.

I hope this has given you some new things to consider with your concussion patient.  Next week, we will continue this discussion to look at how movement impacts athletic performance.  Stay tuned as I am super excited to share with you.  If you enjoy this blog, please share with your colleagues, athletes and training partners and please be sure to follow us on instagrm @ bjjpt_acl_guy and twitter @acl_prevention.  Train hard and stay well.  #ViPerformAMI #ACLPlayItSafe

Dr. Nessler is a practicing physical therapist with over 20 years sports medicine clinical experience and a nationally recognized expert in the area of athletic movement assessment and ACL injury prevention.  He is the founder | developer of the ViPerform AMI,  ViPerform AMI RTPlay, the ACL Play It Safe Program, Run Safe Program and author of a college textbook on this subject.  Trent has performed >5000 athletic movement assessments in the US and abroad.  He serves as the National Director of Sports Medicine Innovation for Select Medical, is Vice Chairman of Medical Services for USA Obstacle Racing and movement consultant for numerous colleges and professional teams.  Trent also a Brazilian Jiu Jitsu purple belt and complete BJJ/MMA junkie. 

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