The primary findings of this study indicate that 6-week corrective exercise intervention improved the overall FMS® score of the female netball players. However, the magnitude of change and the lack of changes in most of the individual tests, demand caution when interpreting these results. To the author’s knowledge, this is the first study to demonstrate these effects using intervention and control groups in netball.
When interpreting the effect of the intervention, consideration should be given to the age and gender of the population, type of sport or physical activity, and type and length of the intervention. In this study, we incorporated FMS® recommended intervention with the standard strength and conditioning program and found that adding corrective exercises partially improves the functional movements relative to strength program alone. The significant increase in overall score is also reflected on the increase in number of players scoring above 14 in the intervention group relative to control (a score identified to arguably predispose athletes to injury [6, 17]. These improvements are in agreement with the few studies that examined the effect of intervention on FMS® score, although on male mixed martial artists [5] and predominantly male firefighters [18].
However, the increase in score of the intervention group can be attributed only to changes in ASLR, TSPU and potentially the hurdle step scores of the intervention groups, as shoulder mobility, in line lunge, deep squat and rotary stability did not differ between groups. These results are somewhat expected as FMS® intervention is largely based on core stability and control, while tests for which overall upper and lower body strength is required, have improved the same over the course 6-week for both groups. Hence, including few core corrective exercise into a “standard” strength and conditioning program might have a similar effect as including additional training with focus on FMS® corrective exercises.
Another component of improvement to consider when interpreting these results is the magnitude of improvement in the FMS® score. In this study, both groups were within 1 point from the injury cut of score of 14 in pre-testing, hence improvement by one point in any of the tests would shift players from being at risk of injury to less predisposed to injury. Consequently, although the number of players above the injury factor of 14 increased in the intervention group, the mean score was 14.5, an improvement of only 1.5 points. The size of improvement is comparable to other studies, but differences in sample population, type and length of the intervention should be considered during comparison. For example, in a study by Bodden et al. [5] male mixed martial arts athletes improved about 2 points after 4-week intervention, while Kiesel et al. [17] show 3 point improvement after 7 week intervention on professional football players. Additionally, Frost et al. [19] showed an improvement of only 0.4 points on total FMS® score on two different 12-week intervention programs on firefighters. Both Bodden et al. [5] and Kiesel et al. [17] studies conducted 4 sessions per week, while Frost et al. [19] used 3 sessions per week, similarly to this study. These results indicate potential confounding factors that extend beyond the differences in population and intervention methodology. Hence, volume and number of sessions during intervention is also highly individualized and may not necessarily reflect on the improvement in the FMS® score.
Previous studies have suggested that scoring criteria in FMS® could be amended to account for these scoring limitations, as a midrange score of 2 for example, may be given to an athlete with a wide range of movement limitations or patterns [5, 19]. In this study, this is evident from the shoulder and rotary stability tests, as all athletes scored 2 in pre and post testing even though some players might have improved the degree of compensation. This kind of scoring does not accurately reflect on all sports where certain limitations resulting from sport participation do not necessarily indicate predisposition to injury, or are not relevant to the specific sport. This may be the reason why several studies found limitations in using FMS® to identify movement deficiencies related to athletic performance in male [10] and female athletes [20], or general performance tests [21] including core stability [22].