Modified Functional Movement Screen as a Predictor of Knee Valgus in Male Soccer Players

Abstract

INTRODUCTION: The Functional Movement Screen (FMS) is a battery of seven tests to observe key movement patterns and is scored in a twenty-one point scale (Cook 2010). Studies have suggested that individuals with scores of 14 or less had significantly higher risks of injury (Bushman et al., 2015; Chorba et al., 2010). A modified FMS, scored in a ten-point scale, has been used by a Division III college athletic training staff. It includes three original FMS tests (deep squat, hurdle step, shoulder mobility) and a single-leg squat (scored as 0 for knee valgus, and 1 for no valgus). It is not known whether the new battery can predict knee valgus in Division III male soccer players. PURPOSE: To determine whether the modified FMS can predict knee valgus when landing from drop jumps. METHODS: Seventeen Division III male soccer players and twenty healthy male non-athletes (ages 18-24) were recruited for the study. Subjects performed all modified FMS exercises and were scored by one FMS certified athletic trainer. Reflective markers were placed on subject’s tibial tuberosity and distal tibia to define the tibia and knee valgus angles were measured with respect to the vertical line from video via goniometry at the lowest point of during landing from a drop jump from a 31cm box. RESULTS: For the soccer group, the mean for modified FMS score was 7.33 ± 1.63, mean left knee valgus was -1.73 ± 1.62 degrees and mean right knee valgus was -0.73 ± 1.87 degrees. The controls’ mean modified FMS score was 6.85 ± 1.50, mean left knee valgus was -2.6 ± 2.80 degrees, and mean right knee valgus was -1.35 ± 3.23 degrees.The modified FMS was not a significant predictor of right knee valgus (p=0.65) or left knee valgus (p=0.22). CONCLUSION: The Modified Functional Movement Screen is not a significant predictor of knee valgus in DIII male soccer players. More sensitive scoring could have improved the modified FMS’s ability to detect knee valgus. Post hoc power analysis results suggest that the non-dominant side may be more relevant for assessment.