Fundamental movement skills (FMS) are building blocks of more advanced movements, including subdomains of locomotion, object control and balance skills, but limited evidence exists for this three-factor structure. The aim of this study was to examine the structural validity of a three-factor modified test battery of FMS across age and sex in two large samples of preschoolers aged 3-6 years (sample 1: n = 1213, mean age 4.8 (.09); sample 2: n = 1198, mean age 4.3 (.09)). We used a test battery of FMS consisting of movement tasks for locomotion (run, horizontal jump and hop) and object control (catch, overhand throw and kick) from the Test of Gross Motor Development and balance skills (single-leg standing, walking line backward and walking line forward) from the Preschoolers Gross Motor Quality Scale. Confirmatory factor analysis was used to analyse the data. We found support for both a three-factor and a two-factor structure. Measurement invariance testing showed invariance over age and partial scalar invariance over sex. We conclude that our modified test battery is an appropriate measure of young children's FMS across the domains of locomotion, object control and balance, but that locomotion and object control subdomains provide limited unique information.
Keywords: Fundamental motor skills; confirmatory factor analysis; measurement invariance; preschoolers; structural equation modelling.