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.