Can a Functional Movement Screen really help your performance?

If you've joined a gym recently, you were probably offered a free fitness assessment. There are numerous different assessments available to exercise professionals. One of the more popular screening tools is the Functional Movement Screen (FMS). The FMS was developed as a tool to identify movement asymmetries or major limitations in movement patterns. The underlying principal of the FMS is that movement quality is essential to reducing injury and optimizing performance. It is used to identify limitations or asymmetries in 7 fundamental movement patterns. The screening places an individual in extreme positions where weaknesses and imbalances become noticeable if appropriate mobility and motor control is not utilized. The focus of the FMS is movement quality and to identify any movement deficiencies or limitations. Individuals must not have current pain or musculoskeletal injury.

The Functional Movement Screen consists of 7 specific tests and 3 clearing exams. The 7 tests are the hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability push up, and rotational stability. The scoring system used is a 0-3 scale with 0 being a painful test and 3 being the highest score possible. 5 of the 7 tests are performed bilaterally looking for side-to-side differences as well as a combined score for the test.

The 3 clearing tests are the active impingement, spinal extension, and spinal flexion tests which are scored positive or negative for pain.

The FMS is used to assess an individual's movement quality and asymmetries to help better design exercise or training programs which should allow a safe progression to higher level exercises/training. The theory is that by addressing any dysfunctions noted on the FMS, one can reduce their risk of injury and improve their performance in sports. Let's look at the published research on the FMS and see what it says.

Reliability

There are numerous studies looking at the reliability of the FMS screen with varying results. Overall, the studies show good to excellent intrarater reliability (the same assessor) for both experienced and novice assessors. There is generally fair to good interrater reliability (between assessors) in most published studies as well.

Movement Dysfunction

A study by Frost in the Journal of Strength and Conditioning Research from 2013 questions the ability of the FMS to assess dysfunction. They looked at 21 firefighters who initially performed a standard screen followed by a repeat screen 5 minutes later. The participants were provided with a verbal description of the grading criteria immediately before performing each task during the second screen. All firefighters improved their scores within minutes of being told what movement patterns were required. The authors conclude that it may be inappropriate to assume that movement patterns are the direct result of a specific "dysfunction" or "impairment" that could be rectified via "corrective" exercise.

Injury risk

Keisel has published two studies involving NFL players showing that a total score of less than 14 or an asymmetry on any of the bilateral tests place players at a higher risk of injury. Players' having both a total score of less than 14 and one or more asymmetries are at an even greater risk of injury. Lisman published in the journal Medicine & Science in Sports & Exercise in 2013 that military recruits who had a 3 mile run time less than 20.5 minutes and scored less than 14 on the FMS were 4.2 times more likely to experience an injury. These two studies support an overall score of 14 as the cut off for increased injury risk.

However, a study by Warren in the Journal of Sports Rehabilitation in 2014 showed a poor correlation with scores and asymmetries for both contact and non-contact injuries. In another article by Dossa in Journal of the Canadian Chiropractic Association in 2014, they concluded that the FMS couldn't be recommended as a pre-season screening tool for injury prevention in major junior hockey players.  Lastly, McCall gave a recommendation of "D" for the FMS as a screening test to identify professional football players (soccer) at risk of injury in the British Journal of Sports Medicine 2015.

Sports performance

A 2011 study by Parchmann in the Journal of Strength and Conditioning Research found that there were no significant correlations between the FMS and on the field sports performance tests whereas the 1 rep max back squat showed a significant correlation to these field tests. Lockie in the Journal of Strength and Conditioning Research in 2015 found few significant correlations between FMS scores and multidirectional speed and jumping tests. Lastly, Okada published in the Journal of Strength and Conditioning Research in 2011 that core stability and the FMS are not strong predictors of sports performance.

All this research shows that the FMS is a reliable screen able to score movement patterns and assess for side-to-side asymmetries. It may not truly assess movement dysfunction and may just be showing unfamiliarity with the activity, which may be easily improved with verbal cuing and repeat performance. The research shows conflicting studies on whether or not it can predict injury risk in a variety of sports. Lastly, the research shows little correlation with specific sports performance tests and FMS results.

So, what does this all mean? Does the FMS truly screen for movement flaws or is there a spectrum of what constitutes "normal" movement? The FMS still shows potential for assessing an individual's risk of injury but it should not be the only criteria as risk is multi-factorial and the FMS may not be specific enough to detect all of the underlying components. Although research doesn't show any significant relationship between the FMS and specific sports performance tests, there may still be a correlation between FMS scores and how well and individual does in a specific sport. Sports performance tests, such as the 40-yard dash, do not show a high correlation to specific indicators of success in sports (ie batting average, points per game, touchdowns scored, etc).

My personal experience with the Functional Movement Screen is that it is a great tool to quickly assess "healthy" athletes for "abnormal" movement patterns that may be secondary to limitations with mobility and stability. However, it should not be the only assessment used and should not take the place of a more detailed individual assessment looking at specific areas such as joint ROM and mobility, specific muscle strength testing, on-the-field testing (ie pro agility), and fitness testing (ie beep test).

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