There are a variety of "movement screening systems", most notably FMS - "Functional Movement Systems", developed in 1997 - that purport to screen for injury risk in physical activity. The hypothesis is that inefficient movement patterns, restrictions in mobility, weaknesses in "core strength", etc., create "compensatory" movements that increase the risk for injury. Once "dysfunctions" in movement are identified, a suite of "corrective exercise" is prescribed under the presumption that this will reduce pain and injury risk.
In my own research on FMS, I was initially a pretty staunch defender - you can comb Google Scholar and find small studies claiming a statistically significant effect in predicting injury rates among various specialty populations, like soccer or football players. Low FMS scores are, in these studies, associated with higher injury risk.
However, a closer examination of the science reveals some deep-seated problems with its design, scope, and reliability. It's a case, as it often is in fitness fads, of the marketing cart being ahead of the research horse. Two research reviews published in the British Journal of Sports Medicine found the quality of FMS research to be generally quite poor, and better controlled research has failed to substantiate the claims of FMS practitioners.
So, the article below from PainScience.com is a very richly-cited and thorough examination of the problems with FMS. Some notable takeaways:
- FMS screening cannot detect people who are already injured, which casts serious doubts on its ability to predict future injury.
- As a diagnostic tool, FMS cannot identify causal variables for "pathological" movement, such as someone in the early stages of a neurological disorder. Without being able to identify a causal mechanism, the "treatment" of corrective exercise protocols is inherently unreliable.
- Telling someone they have a poor FMS score can induce false beliefs about injury risk, prompting them to move less or avoid progressive load out of an unfounded fear of being injured.
- The criteria for ideal movement patterns development for FMS screening is arbitrary. There are no movement patterns known to be associated with generally increased risk of injury, and that's because.....
- The human body is remarkably adaptive. Think for example of Armand Poireaux, the young French CrossFit athlete who gained fame for performing a 155lb clean despite having cerebral palsy. Virtually nothing about his movement conforms to FMS-type standards of movement (much less the standards of Olympic weightlfting), yet he and others with neurological disorders are able to exercise without pain or heightened injury risk.
- Finally, the most consistent predictors of injury rates among athletes are training load and volume. Heavy load performed under fatigue reliably increases injury rates:
A deeper problem is that FMS has now been practiced for over 20 years. No small number of fitness professionals carry various FMS certifications and make regular use of it in practice. Even after the research rolls in and shows it to be an unreliable diagnostic and corrective tool set, it can be extremely difficult to convince people who are deeply invested in it to change course.