*2.1. Eligibility Criteria*

Articles assessing proficiency in FMS, locomotor skills and object control skills in children aged 3 to 6 years were included in this systematic review and meta-analysis. Studies were selected if they met the following criteria: (1) children aged 3–6 years; (2) scores reported by age and gender, if the study is an intervention study, with a baseline data report required; (3) results assessed using the Test of Gross Motor Development scale (TGMD), including modified versions; and (4) outcome measures reported using raw scores.

We excluded studies that met any of the following criteria: (1) review articles, conference abstracts or books; (2) participants not being assessed simultaneously according to age and gender; (3) inclusion of special populations such as those with disabilities or diseases; and (4) studies not published in English. We calculated the pooled effect size through meta-analysis.

Inclusion and exclusion criteria were formulated and applied by two reviewers (Y.Z. and M.K.) independently, and in the case of disagreement, they were confirmed by another reviewer (W.Y.).
