Asymmetry during Functional Movement Screening and injury risk in junior football players: A replication study

Abstract

An indicator of movement quality and potential injury risk during Functional Movement Screen (FMS) testing is the presence of asymmetry when comparing the left and right sides of the body. The aim of the study was to investigate the reproducibility of the injury risk model proposed in our previous research (Chalmers et al. 2017; derivation study) that showed an increased injury risk for elite junior Australian football players demonstrating ≥2 asymmetrical FMS subtests. We used a direct replication design. Players underwent pre-season FMS testing, and an injury surveillance system monitored 277 male participants during the subsequent regular season competition. Designated club officials monitored the weekly competition participation of players. The definition of an injury was "a trauma or medical condition which caused a player to miss a competitive game". Cox proportional hazards regression models were used to investigate the relationship between asymmetry and number of games played before first injury (ie, survival time). The level of reproducibility was determined according to statistical significance, effect size, and subjective assessment. Demonstrating asymmetry during FMS testing was not associated with a significant increase in prospective injury risk in the replication study (P > .05). Moreover, effect sizes (hazard ratios) from the derivation dataset were not within the 95% confidence intervals of the respective asymmetry predictor in the replication dataset. Subjectively, researchers were in agreement that the findings from the derivation data were not successfully reproduced. Clinicians and researchers should be cautious about using FMS asymmetry findings to derive injury risk for junior football players.

The association between physical fitness level and number and severity of injury and illness in youth elite athletes

“…Second, pre‐season physical fitness tests were of limited value in predicting new injuries in two prospective studies on male elite youth football players (n = 84 and n = 67) . Finally, in a prospective study on 382 male elite junior Australian rules football players, an association between physical fitness compounds (lower aerobic endurance, greater sprint, and agility performances) with increased injury risk was first demonstrated, but not reproduced …”

“…Numerous studies related to various elements of physical fitness have attempted to identify factors that contribute to injury and illness risk in young athletes, although not at the elite level. Typically, physical fitness tests encompass components such as cardiorespiratory endurance, muscular strength, flexibility tests, and functional movement tests . Prior research studies on the adult population have demonstrated an association between higher levels of aerobic fitness and decreased injury risk, whereas research on the relationship between physical fitness level and illness risk is limited and mostly focus on increasing training loads .…”

“…Prior research studies on the adult population have demonstrated an association between higher levels of aerobic fitness and decreased injury risk, whereas research on the relationship between physical fitness level and illness risk is limited and mostly focus on increasing training loads . For youth elite athletes, there are even less data addressing the relationship between physical fitness and injury and illness risk and the results are conflicting . While some studies claim that well‐developed aerobic fitness might protect youth athletes from future injury or illness, no association has been shown with functional movement screening tests, nor with a relatively lower fitness level …”

“…For youth elite athletes, there are even less data addressing the relationship between physical fitness and injury and illness risk and the results are conflicting . While some studies claim that well‐developed aerobic fitness might protect youth athletes from future injury or illness, no association has been shown with functional movement screening tests, nor with a relatively lower fitness level …”

Relationship between movement dysfunctions and sports injuries according to gender of youth soccer player

“…In studies on FMS and sports injury in soccer players, Chalmers et al (2018) investigate the relationship between FMS asymmetry and number of games played before first injury and reported to be closely associated with a significant increase in prospective injury risk ( Grygorowicz et al, 2013 ; Miller and Susa, 2019 ; Sprague et al, 2014 ).…”