Functional movement is negatively associated with weight status and positively associated with physical activity in British primary school children

The paper for this journal club was related to functional movement, physical activity and weight in children.

Duncan M, Stanley M. Functional movement is negatively associated with weight status and positively associated with physical activity in
British primary school children. Journal of Obesity 2012.

What was the aim of the paper?

The researchers were aware that there was a lack of research on the structural and functional limitations of excess weight in children. The aim of their research was to look at the relationship between physical activity, functional movement and weight in children. The authors were from the Department of Biomolecular and Sport Science in Coventry University in the UK.

What did the study involve?

58 British school children (mean age of 10.7 years, over 80% Caucasian) were recruited for the study. The researchers measured body mass and height and calculated BMI. The children were classed as overweight or obese according to the International Obesity Taskforce (IOTF) criteria. Physical activity was measured using pedometers which the children used over four days (2 week days and 2 weekend days). Functional movement was assessed using the Functional Movement Screen (FMS). This included seven tests (deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, truck stability push-up and rotary stability) and the children were given three trials of each test. The researchers took the highest score from the three trials for each test and used this to create a FMS score.

What were the main results?

The researchers found that FMS was negatively associated with BMI and positively related to physical activity. Normal weight children score significantly better for FMS score compared to overweight or obese children. BMI and physical activity were also significant predictors of FMS score, with BMI being a stronger predictor.

What can we take from it?

This was an enjoyable study to read with a simple research design. It would have been good to see a larger sample size with children of different ages and from different parts of the UK, not just Coventry. I would have also liked to have seen a power calculation for the sample size needed for this study.

The research design was explained clearly, but I feel like specific details about times of measurement of BMI, FMS and physical activity levels would have been helpful to give a better insight into the research. As Jon mentions, it’s well-known that BMI may not be completely accurate for body fat measurement, but the author Mike said that they used it because it’s used as part of the national child measurement programme. Mike also believes that he probably wouldn’t have reached a different conclusion if they had measured adiposity directly.

I’ve picked out the following comments about the research.

  • Although the sample size was small, it gives a positive indication that this topic requires further research, with larger sample sizes. 
  • It may also be relevant to extend the objectives of this study to a wider age range, such as 8 to 16 year olds, to compare any differences between FMS score and physical activity across an age range.
  • My concern is how can a test (FMS) be utilized for two different populations and come to useful and reliable conclusions?
  • Can the level of obesity be more categorically reported than BMI?
  • I think it would be interesting to see whether an intervention of exercise, diet, or exercise + diet significantly improves FMS score, to see what extent functional skill or functional limitation effect movement.
  • we should consider the implications of reduced functional movement, altered gait, and lower body loads on the design of exercise prescriptions in overweight children.

Overall, this was a simple study that adds to the little research that has been carried out on physical activity, functional movement and obesity in children. Mike now wants to see what impact a physical activity intervention might have on children’s obesity and functional movement.

You can see more comments, questions and answers from fellow Sport Scientists and the author Mike here.

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7 Comments

Filed under Physical activity and children

7 responses to “Functional movement is negatively associated with weight status and positively associated with physical activity in British primary school children

  1. This was an interesting study, and easy to read. This study has addressed an important gap in the literature with respect to the population. Functional movement in normal and overweight children has been researched to a lesser extent, and with more research looking at biomechanical aspects such as lower body loads and gait.

    Although the sample size was small, it gives a positive indication that this topic requires further research, with larger sample sizes. It may also be relevant to extend the objectives of this study to a wider age range, such as 8 to 16 year olds, to compare any differences between FMS score and physical activity across an age range. As for the measures used, I think it would be nice to also see measures of muscular strength/endurance, but I thought the research design was good.

    The results provide several areas for future research. As BMI was a strong predictor of FMS score than physical activity I think it would be interesting to see whether an intervention of exercise, diet, or exercise + diet significantly improves FMS score, to see what extent functional skill or functional limitation affect movement. Or in other words would an increase in physical activity alone increase functional movement, or would a reduced body weight be more effective. Perhaps first though we should consider the implications of reduced functional movement, altered gait, and lower body loads on the design of exercise prescriptions in overweight children. For example which activities will prevent injury, improve movement patterns, and reduce body weight whilst promoting adherence. As we’re competing against televisions and xboxs, a child needs to exercise on their own accord, so it needs to be appealing. We could research and produce the most effective interventions to help them, but if they don’t want to do it, they most probably won’t.

    • Some great observations. We were really trying to explore the area of functional movement in children, particularly with the FMS as it seemed to us to be a user friendly way we could assess functional movement in schools. I think you have hit the nail on the head though, we really now want to see what impact a physical activity/exercise intervention might have on children’s obesity and functional movement. Plus, whether we have better or poorer impacts with different types of intervention. There is some good but limited research which shows more overweight childrne actually become more motivated wiht resistance exercise interventions because they can usually lift more mass than their normal weight peers which, in turn, makes then feel greater mastery than other children.

  2. Some questions about my limited knowledge on the functional movement screening. The interrater reliability either correlation coefficients or intra-class correlation coefficient was not given. I did read a recent study (Minick, et al. 2010; PMID: 2007205) that determined interrater reliability can be confidently applied by trained individuals. My second question is if the raters were blinded to the study? Possibly knowing what the study was about could have modified scores given?

    I tried to look up the studies that were cited about this FMS but was not able to do so. Is this test done for the athletic population, if so how does this relate to the diseased or obese and are there norms for this population? The score 15.6 vs 10.6, though significant difference, is it really bad?
    I thought the researchers did a good job answering the questioned asked. However, there needs to be more clarification about the test utilized. I came across one study utilizing this in female collegiate athletes (PMID: 21589661) and a score less than 14 showed an increase for injury. Collegiate athletes are able to score 14 or less, similar to young normal or obese children. My concern is how can a test be utilized for two different populations be utilized and come to useful and reliable conclusions?

    I understand that this study was most likely one of the first to utilize this and does give further insight to how obesity can negatively affect movement in children. Furthermore, research in this area should look at other populations. In the United States, non-Caucasians have a higher risk in disease related complications due to obesity. Lastly, I thought this study was important in looking at obesity at an early stage in the lifespan and how it may negatively influence movement, which may contribute of nonactivity in young children and is added to the evidence that inactivity may lead to obesity.

  3. An interesting study and in a very relevant area of exercise science. The issue of effective movement is fundamental to developing the skills that will serve us as adults in everyday life and those of the population who aspire to elite level sport. With the trend for exponential growth in obesity in children, coupled with the decreases in physical activity this should go some way to explore the role of general movement patterns and how they affect engagement in physical activity.
    A couple of points that come to mind for me are:
    1. Like Exercisephysiologist I would also like to know more about the interrater reliability of what is largely a subjective tool.
    2. Can the level of obesity be more categorically reported than BMI?
    I think that as the authors point out in the discussion the effects of motor learning on performance of the FMS would also help define if these results could be modified without the concomitant increase in physical activity.
    I do believe that this paper will help stimulate the growth in understanding the role that movement can play in enhancing the physical activity experiences of school children. But more importantly if this type of screening is carried out, it could help those defined as obese/overweight with the prescription of exercise as I’m sure obesity changes the way children move. Therefore we could look to find the appropriate exercise prescription for a child depending on their weight and fitness.

  4. Mike Duncan (@MikeDunky)

    Again, some good points. In terms of interrate reliability, we used the weighted kappa to examine this. This is in line with other studies examining the FMS and across all exercises the agrement between testers was rated as ‘excellent’ with kappa values all in excess of 0.8. The FMS raters were blinded to the study, so hopefully that reduced potential bias effects

    The FMS was originally conceptualised as a tool to assess the functional movements that underpin all movement. So although most of the prior work has been conducted with trained athletes it seemed logical to us that the FMS could equally be employed to assess functional movement generally. Gray Cook’s series of books also supports this and are useful reads if anyone is interested further.

    The benchmark value of 14 comes from one paper in American footballers based on odds ratios of injury. There are also a range of issue with this paper and how the authors came to the 14 benchmark which have potentially skewed the wider understanding of the FMS. In essence if we take the FMS score as a whole a higher score relates to better functional movement and a lower one poorer functionality.

    The whole issue of BMI to categorise obesity is well know and we only used BMI as it is the way in which the UK government distinguish weight status in children as part of the national child measurement programme. In all honesty though i am not sure we would have reached a different conclusion if we had actually measured adiposity directly.

  5. Carla Gallagher

    Very interesting read on a subject relating to a highly topical area of research.

    I had similar thoughts to Faye and exercisephysiologist on other studies. I just have one additional question during the study did you observe whether the children in the overweight group found certain exercises more difficult than others i.e. did they cope better with upper body exercises as opposed to lower body exercises. Could FMS scores be split in to upper and lower body scores?

  6. Pingback: Week 8 journal club summary | Becky Canvin

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