Functional Movement Screen Research: 2011 Summary and Review

To the best of my knowledge, there were six major studies published in 2011 on the Functional Movement Screen.   Although there are many qualitative justifications to justify having the FMS in the toolbox, it is important to respect the evidence in the field, whether it comes via formal research or is the product of anecdotal coaching observation.  It may surprise the mass athletic consumer, but what is popular at the moment is not necessarily what is effective.  

This lesson is important especially in January and February when the market is flooded with “new” methods to usher in the new year.  Doesn’t mean we need to carry a stack of research papers to every training session, but coaches should always respect what the research has to say.  We may interpret the research in a certain way after careful consideration of the methods and its applicability to the real world, though as Dr. Jack Daniels is fond of saying, “Not enough coaches know enough science, and not enough scientists know enough about coaching.” 

Okada T, Huxel KC, Nesser TW.  Relationship between core stability, functional movement, and performance.  J Strength Cond Res. 2011 Jan;25(1):252-61.

My initial response when reading the premise of this study was…Huh?  Before getting into the findings of this study, let’s take a moment to explore what exactly a SCREEN is.  Screens exist in various areas of healthcare (blood pressure, eye charts) but also in daily aspects of life that we don’t even think about.  Cars have screens for things such as the oil level and temperature of the engine.  These gauges don’t tell us which car will go from 0-60 the fastest or which can corner the best…they just alert us if there’s a risk the car won’t work.   That might seem like an elementary role but imagine what driving your car would be like without those screens to alert you as to its functionality.  Now do you see the value of a movement screen?

This study took participants through an FMS, a series of three core stability tests, and another series of performance tests (shuttle run, med ball throw, and single leg squat).  Authors concluded that core stability and functional movement are not predictors of performance.  My question: who said they were?   

For the authors to even suppose a link between the FMS and performance is dubious.  On a broad level, you might expect some correlation in that the FMS looks at motor control, just as any physical task is likewise a measure of motor control.  However, you might also find a broad link between a blood pressure reading and VO2 max as both are measures of the cardiovascular system.  Yes, on a broad level, there will be a certain level of correlation, but these measures are designed to identify different things and have different purposes to streamline athletes/clients/patients toward the best intervention.  Even if this study did find a link between functional movement with core stability and performance, it still would not have told us very much, in my opinion.  

Kiesel K, Plisky P, Butler. Functional movement test scores improve following a standardized off-season intervention program in professional football players.  R.Scand J Med Sci Sports. 2011 Apr;21(2):287-92 

Here is a study in which we can have confidence in the quality of interventions since this was conducted by a team of the leading FMS researchers.  However, one of the criticisms of the study is a perceived conflict of interest with FMS faculty conducting the study.  Nevertheless, the study did indicate that FMS scores can be improved with certain interventions.  Key points:

• Players were provided a standard intervention protocol
• 41 out of 62 players were free of asymmetries following intervention
• Conclusion: more study needed to determine if improving beyond standard injury threshold score of 14 and/or removing asymmetries improves injury resistance  

Schneiders AG, Davidsson A, Hörman E, Sullivan SJ.  Functional movement screen normative values in a young, active population.  Int J. Sports Phys Ther.  2011 Jun;6(2):75-82.

This study asked the simple question: where do most people score in the FMS?  Normative values exist for other measurements like blood pressure, heart rate, blood sugar, and performance measurements like VO2max, vertical jump, and 40yd dash time.  To better understand any data, it helps to know what ranges are normal so we can identify risk in those who are abnormal.  However, data can also be used to predict performance in certain contexts.  Noteworthy findings: 

• Average of 15.7 score average among sample of 18-40 yr old active individuals. 
• No statistically significant difference between males and females in total score though there was significant divergence in selected screens.  Males performed better in stability screens (Trunk Stability Push Up and Rotary Stability), while females performed better in mobility screens (Active Straight Leg Raise and Shoulder Mobility).
• No statistical significance between those with or without prior injury.   This point is one often used to critique the FMS as insensitive to prior injuries, but how one actually defines “injury” is a major issue.  In the competitive athlete realm, injury concealment is common.  Does “injury” mean missed time?  Does it mean simply a diagnosis?  Or can it mean unreported conditions that alter motor control even if they don’t lead to lost time in competition and/or practice. Studies are inconsistent in how they classify injury, which can make it hard to evaluate sensitivity across studies.  (See Research Review: The Functional Movement Screen and Female Athletes) for a study with additional discussion on this topic. 
• 33% scored 14 or below.  14 has been shown as the marker of increased injury risk in previous studies (Kiesel, 2007)
• Interrater reliability was high.  Consistent with prior studies (Minick 2010)

Frost DM, Beach TA, Callaghan JP, McGill SM.  Using the Functional Movement Screen™ to evaluate the effectiveness of training.  J Strength Cond Res. 2011 Sep 14.

One thing lacking from previous FMS research is information on the effectiveness of corrective exercises.  This study (note the presence of Dr. McGill on the research team) found no significant FMS score changes between two groups exposed to corrections and the control group that did not go through corrective exercise.  Does this mean that FMS corrections are a waste of time?  No…this study just tells us that we need to know more details about corrections. 

Even in the full text of this study, it was unclear what methods were used to correct the faulty patterns.  Although interrater reliability has been shown robust among trained FMS screeners, the skill to administer corrective exercises can vary widely.  Ultimately, I don’t know that we can make any profound conclusions from this study other than to be reminded that many variables play a role in the effectiveness of corrections.   

Parchmann CJ, McBride JM. Relationship between functional movement screen and athletic performance.   J Strength Cond Res. 2011 Dec;25(12):3378-84.

This study was another head scratcher… “The lack of relationship [between FMS and performance measures] suggests that FMS is not an adequate field test and does not relate to any aspect of athletic performance.”  Huh?

In this study, researchers looked at a sample of college golfers (both men and women) and conducted a battery of performance tests: sprints, agility test, vertical jump, 1RM squat, and club head speed measurement.  They also conducted an FMS on each player.  Based on their results, FMS was not correlated with any measures of performance. 

Medical researchers don’t try to poke holes in the validity of blood pressure by testing it as a measure of cardiovascular performance.  Yet that’s basically what the researchers did in this study.  We have ranges of abnormal and normal to identify risk stratification.  The use of blood pressure, just as with the FMS, is to triage a situation on first contact with a client/athlete/patient, and have a standard baseline upon which to measure progress with follow up interventions.  As with the study listed above, this was another case of testing the FMS for something that it isn’t. 

O'Connor FG.  Deuster PA. Davis J. Pappas CG.  Knapik JJ.  Functional movement screening: predicting injuries in officer candidates.  Med Sci Sports Exerc.  2011 Dec;43(12):2224-30.

Perhaps the study that’s of greatest interest to me…Over 800 Marine Corps Officer Candidates studied during medical inprocessing, which is a 2-3 day period of medical testing, fitness testing (pull ups-crunches-3 mile run), and other administrative procedures occuring before real training begins.  The sample included candidates from both the long course (10 weeks) and short course (6 weeks for college students who go two consecutive summers).  Key points:

• Score of 14 considered robust predictor of injury in this group.
• Average score 16.6.  Seems a bit high, in my opinion, but that’s just an opinion.  Again, research says interrater reliability is high, but medical inprocessing can be a frantic environment and MCB Quantico.  Surely the scores could have been artificially deflated as well as inflated, but in that setting there is reason to be skeptical of the scores. 
• Inverse relationship between score and injury prediction above 19.  In other words, you are more likely to get hurt if you have an FMS score above 19 versus 15-18.  If true, this supports the FMS message that symmetrical 2’s for a total score of 14 is the key benchmark for injury prevention.  Much like the blood pressure, it doesn’t pay necessarily to have an outlier score. It might also be a statistical oddity as well.  However, given the correlation between PT score and FMS score, it could be that those candidates with greater physical capacity also have greater abilities to push themselves into injury. 
• High correlation between PT scores and FMS score.  79.8% of candidates who scored less than or equal to 14 also scored less than 280 (out of 300) on fitness test (PFT).  Only 6.6% with scores greater than or equal to 280 scored 14 or below.
• No evidence of asymmetry being linked to injury in this sample. 

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