The Functional Movement Screen and Running Injuries

To be honest, the Functional Movement Screen is not something that I have really paid a lot of attention to. It is becoming a popular topic and attracting increasing attention. I have scanned some abstracts on it periodically, but it never really grabbed my attention. There have been a couple of studies of it in runners (here and here), but they were just descriptive studies and not of much use. The Functional Movement Screen is a screening tool that gives a score based on seven tests: the Deep Squat, Hurdle Step, In-Line Lunge, Shoulder Mobility, Trunk Stability Push-Up, Active Straight Leg Raise, and Rotary Stability. Rather than go into detail here, I refer you to these two blog posts by Chris Beardsley and Paul Ingraham for more good information. Even though the two studies just linked provided normative data in groups of runners, I did not think that it would have a great deal to do with overuse injuries in runners which is probably why I did not pay a lot of attention to it.

Having said that, I just recently did pay some attention to it due to the appearance of this masters thesis from the California State University:

Predicting injuries in NCAA runners using the Functional Movement Screen (FMS(TM))
Padilla, Ricardo, M.S.,
CALIFORNIA STATE UNIVERSITY, FULLERTON, 2014
The Functional Movement Screen (FMS) has shown some efficacy in predicting injury in several different populations. However, no research has examined whether the FMS can predict injury in repetitive motion athletes, such as runners. This study will examine whether the FMS can prospectively predict injury in a group of collegiate (Division I) sprinters and cross-country runners. 64 division I collegiate runners (31 sprinters, 33 cross country) volunteered for this study (35 male, 29 female, age = 19.26±1.16, height = 1.74±0.09m, weight = 63.4±8.9kg). FMS testing was performed and injuries were then tracked throughout the athletic season. Athletes who sustained injuries (FMS Score: 15.9±1.9) had a significantly higher (p < 0.05) FMS scores than those who were non-injured (FMS Score: 14.6±1.9). Logistic regression revealed that the FMS was a good predictor of injury and a one unit increase in FMS score resulted in an increased risk of injury by 1.5 times (P = 0.0 139; 95% confidence interval = 1.1-2.0). The ROC curve resulted in a poor score (<0.70) and was not able to identify cut points for injury prediction. Unexpectedly, higher FMS scores led to an increased injury risk in collegiate runners. It has been suggested that in order to maintain optimal musculoskeletal health, one must have variety in their movements and postures. Since runners do not get variety in movements from their sport/training, perhaps those with lower FMS scores are achieving that variability, and avoiding injury, through their more variable movement patterns.

I don’t have access to the full thesis to evaluate the methods, but nothing jumps out at me as a problem in the abstract. The participants were division 1 collegiate sprinters and cross country athletes, so they are almost elite level runners which means that it may not necessarily be possible to extrapolate the results to non-elite runners.

In the Functional Movement Screen, the higher scores are considered better as the athlete is ‘stronger’, but in this study they showed that you were more likely to get an injury if the score was higher. That is certianly counter-intuitive. As to why, I have no explanation. In the abstract the author offered this:

Since runners do not get variety in movements from their sport/training, perhaps those with lower FMS scores are achieving that variability, and avoiding injury, through their more variable movement patterns

Without seeing any data (which may be further justified in the full thesis), I am not sure I want to go along with that. I am open to anyone who might want to try and offer up a potential explanation.

When I look at the components of the Functional Movement Screen, many are related to “core stability” (even though there is a poor correlation between the Functional Movement Screen and core stability; probably as the Functional Movement Screen measures more than just the “core”). This does raise some thoughts for me: How often do you hear how important core stability is supposed to be for runners; things like “the core is the engine room for running”. I have no doubt that a stronger core is probably better than a weaker core (just like having a strong muscle is better than a weak muscle), but to simply state that it is better and that its the “engine room” is using the wishful thinking fallacy – that is, just making a statement and wishing it was true. It may or may not be true, but you can not make statements and wish or hope it was true. This does not constitute evidence that something is true. I would speculate that the above study suggests (weakly) that the “core strength” is not that important in preventing running injuries.

As always: I go where the evidence takes me until convinced otherwise, and just because you do not like the results of study does not mean you should ignore it.

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5 Responses to The Functional Movement Screen and Running Injuries

  1. eric johnson January 21, 2015 at 5:06 pm #

    1) i could be wrong, but i believe gray cook / Functional Movement Systems dislike the term “strong core” as well. i think outside people lump them together.

    2) i have a special interest in this topic as i’m a recreational runner with a really good FMS score who has struggled with a series of unilateral injuries after trying to run through a hamstring strain a dozen years ago. i can still run but my volume and intensity are quite limited due to a drastic asymmetry in my stride from that original injury (that specialists from all over the US have not been able to identify and correct).

    am very interested to read a follow up to this topic when/if the final data is released.

    great post. thanks craig.

  2. Paul Yerhot February 4, 2015 at 2:38 am #

    Thanks for sharing!

    These findings are definitely surprising. I have trouble agreeing with the authors conclusions that lacking the ability for movement variability increases ones risk for injury.
    After perusing the study I came across something I find interesting. The authors’ definition of an injury is:
    “For the purposes of this study, injury was defined as: 1) A musculoskeletal related injury, 2) one that occurs as a result of participation in intercollegiate athletics, and 3) one that requires the attention of an athletic trainer, an athletic training student or a physician.”

    A rather vague definition and not one specific to over-use injuries. Additionally, they reported 61% of the sprinters and 72.2% of the cross country runners were injured over the course of the season. That is a quite the majority getting injured. As a previous collegiate sprinter this is where my comment is going to start drifting away from the evidence and become more anecdotal. My thinking is that these runners were injured because they are, quote un-quote, “better athletes” based on the FMS ranking. And these athletes were exposed to harder workouts, more race, and even longer competition seasons; therefore increasing their potential for injury. It would be interesting to see the break down of mileage per week and number of races (total and per competition) to see if any trend exists between the more accomplished runners and injury rate.

    Would love to hear your thoughts on this! I have the full article if anyone is interested!

  3. Greg Dea February 13, 2015 at 12:53 am #

    I’ve also had a good look at the full paper. There are some points I disagree with as a very experienced student of, clinician who uses, and critical thinker of, the FMS.

    First, getting a higher FMS score does not a stronger athlete make.
    Second, I agree we do not see exposure data. The raw data isn’t included.
    Third, there’s an assumption early which skews the conclusions throughout – that scoring a 3 on the FMS means these subjects likely have consistent biomechanically efficient movement patterns. This becomes the basis for claiming that those with high FMS scores could have low movement variability. This is incorrect because scoring a 3 only requires 1 of the 3 reps to satisfy criteria.
    Fourth, running is very different in sprinters vs cross country (who typically display lower efficiency and more heel strike compared to sprinters). Thus, splitting the exposure and injury data into sprinters vs XC runners is required.
    Fifth – anecdotally, the medal bracket sprinters, those who get medals at worlds level, typically score 12-14 on the FMS. Working on limitations to increase their score affects their performance negatively. Similarly, athletes who score 12-14 and whose movement patterns deteriorate to scores lower than this also see performance decrements. This implies, as pointed out by Pardillo, that there appears to be an optimal window of movement pattern display in sprinters related to their performance, but not their injury.
    In line with positive running theory proposed by Frans Bosch, a high degree of motor control is required that appears to be stiffness in the springiness of tendons throughout key areas of the body – promoting short contact time and a reduction in leaks in kinetic chain control. Such refined motor control may appear in FMS as lower movement pattern competency, but which has become acquired for the demands of the sport.

  4. Ivan Rivera May 10, 2015 at 1:29 am #

    Greg:

    I actually did some digging on this very study (and I think that Gray Cook talks a bit about it) and it turns out that when you correct for exposure you do find that athletes with a higher FMS have a lower incidence of injury.

    Also, I should note that the FMS instructors are very specific on how a score of 2 is “acceptable” and a score of 3 is “superior.” I was curious about this myself, and they do mean that acceptable—which would amount to an overall score of 14—really does mean acceptable.

    Finally (and I am offering up a comment to the article and Craig this time), the FMS is decently comprehensive when looking at movement patterns, in particular, of motor control quality through a variety of joint flexion/extension combinations, and providing closed-chain and open-chain situations for both.

    It largely omits the foot, though, which I don’t like.

    In any case, I don’t think that greater motor control (inferred by a higher FMS score) would somehow lead to injury.

    To support this, I’ve been looking at studies of Dynamical Systems Theory applied to running, and it turns out that competent runners have greater movement variability as opposed to less-competent runners (cited below). The authors hypothesize that by making very small alterations and corrections in their gait, competent runners are varying which tissues get loaded and stressed, which spreads out the wear and tear.

    http://www.clinbiomech.com/article/S0268-0033(98)90092-4/abstract?cc=y=

    Based on that, I don’t think that what the authors claim in the abstract holds much water.

  5. Dino October 30, 2015 at 7:40 pm #

    At a recent debate between Stu McGill and Gray Cook at Stanford, Stu McGill cites the study and makes of point of saying that you have to control for exposure risk. The point here is that distance runners who scored higher ran more miles and a predictor of injury in the distance running world is mileage. In the occupational medicine world (ex. carpal tunnel in a factory line worker with repetitive hand movement), the number of cycles without sufficient break over years is enough to trigger the injury. The same goes with running. No matter what the FMS score, if exposure isn’t controlled for then the risk will be higher.

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