Monday, May 5, 2014

Does Movement Dysfunction Do More Than Injure ACLs?

Over the course of the last year we have posted a plethora of articles highlighting some of the most recent research related to movement dysfunction (or pathokinematics) and the impact these have on anterior cruciate ligament stress and injuries.  We have also shown the impact that these same pathokinematics have on athletic performance.  Ironically, despite the literature supporting, many have a hard time correlating pathokinematics associated with ACL risk to decreases in athletic performance.  Taking the example here of a DI basketball player, it does not take a biomechanist nor high level performance coach to see that this athlete’s vertical jump and sprint speed would be impacted by his inability to stabilize his lower kinetic chain during single leg activities. 

The performance issue aside, what is the impact of these same mechanics on other non-contact
sport related orthopedic injuries?  Do these mechanics have an impact on hip injuries?     We recently posted the following tweet on our twitter account asking that very question.  Do these movement patterns or could these movement patterns be linked to femoroacetabular impingement (FAI).  FAI is one of the leading causes of hip labral tears in athletics and is one of the most critically emerging injuries in sports medicine that we know the least amount about.  But, is it that complex?

Bedi et al highlights this question in the most recent issue of Sports Health.  In this guest editorial she summarizes this emerging area of sports medicine and explosion of diagnoses and surgical interventions in this area.  She also glosses over but yet highlights a very simple fact that is so often forgotten in research…The Hip Bone Is Connected To The Thigh Bone!   So often in research, things are made so much more complex than sometimes they really need to be.  Case in point.

One big area of research is looking at CAM deformities resulting in femoroacetabular impingement in the hip which is a causative factor for labral tears in the hip and/or hip pain.  Argicole et al published a recent paper in the American Journal of Sports Medicine looking risk factors hip pain, hip osteoarthritis and hip labral tears in adolescent and young male soccer players.  In this study the authors looked at 63 pre-professional soccer players between the ages of 12-19 years of age.  The authors obtained radiographs (x-rays) at the beginning of play then again at follow-up (~2.4 years later).  What they found was that players who more frequently developed CAM deformities (increase bony formation on the femoral head) had not reached skeletal maturation or growth plate closure.  The conclusion of the paper was that formation of this deformity might be prevented by adjusting athletic activities during skeletal growth or until skeletal maturation.  This helpful and aids in furthering our understanding of this complex issue.  But, is it that complex?

Going back to our previous tweet.  Are we making this too complex and is there a clearer or more obvious answer?  Does the athlete depicted here (note – this is in non-fatigued state) develop a CAM and subsequent femoroacetabular impingement because she is skeletally immature or because she had pathokinematics?  Looking at the ground reaction force (GRF) studies, we know that GRFs jump to 4-8 times body weight with sport related activities.  If this athlete is a soccer player and she were fatigued could this be a more significant factor in her developing a CAM deformity and subsequent femoroacetabular impingement?  If GRF are 4-8 times body weight under normal athletic conditions, you can speculate with these types of movements they are much higher.  With that level of force being directly transmitted through the hip, could this lead to bigger factor leading to this deformity?  If that is the case then, is the answer to limit athletic activities or is the answer to correct the problem.

Obviously, most of us would choose the later.  Sports are physical.  If the body is not prepared to meet the demands of the physicality of the sport then tissues will respond, injuries will occur and performance will be impacted.  Improving pathokinematics will not only reduce risk for injury but also improve performance.  Identifying those pathokinematics and improving them will build an athlete to perform and build them to last.

Build Athletes to Perform…Build Athletes to Last!™

About the author: Trent Nessler, PT, DPT, MPT is CEO of A.C.L., LLC and is a practicing physical therapist with 15 years in sports medicine and orthopedics. He has masters in physical therapy and doctorate with focus in biomechanics and motor learning. He is the founder/developer of the Dynamic Movement Assessment™, Fatigue Dynamic Movement Assessment™ and author of a textbook “Dynamic Movement Assessment™: Prevent Injury and Enhance Performance”. Trent is also associate editor of the International Journal of Athletic Therapy and Training and Member of the USA Cheer Safety Council.  For more information, please see our website at

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