Effects of Combined Movement and Storytelling Intervention on Fundamental Motor Skills, Language Development and Physical Activity Level in Children Aged 3 to 6 Years: A Randomized Controlled Trial

The study includes an experimental design (randomized controlled trial), double-blind, repeated measures and parallel groups (6 interventions and 6 controls) considering previous studies and a quantitative approach. The methodology followed will be the Consolidated Standards of Reporting Trials Statement (CONSORT) methodology.

It is expected to recruit 12 children from each classes group (without distinction of sex). The distribution of the classes groups (12 classes group) will be in 3 experimental groups (6 classes group, n ± 72 children) and 3 control groups (6 classes group, n ± 72 children). The distribution by clusters or strata is justified by the fact that the use of individual randomization would imply a high probability of contaminating the control groups, since it is unfeasible to prohibit children interaction in classrooms or school recreational spaces (i.e., playgrounds, hallways, laboratories), which is where the study intervention will be carried out. The sample size calculation indicates that the ideal number of participants per group is 10. As agreed in a previous study, a mean difference of 3.22 total score of locomotor skills domains was used for this calculation as the minimum difference necessary for substantial clinical relevance, with a standard deviation of 0.70 points, considering an alpha level of 0.05 with a power of 80% and an expected loss of 15%. The GPower program (version 3.1.9.6, Franz Faul, Universiät Kiel, Kiel, Germany) will be used to calculate the statistical power.

The 12 classes group will be selected in 4 upper middle level classes (2 experimental and 2 control; age range between 3 to 4 years), 4 transition level 1 classes (2 experimental and 2 control; age range between 4 to 5 years) and 4 transition level 2 classes (2 experimental and 2 control; age range between 5 to 6 years), which will be randomized by stratified sampling, which consists of segmenting the classes that agreed to participate in the study according to educational levels (strata) and then performing a random sampling on each one of them, using R statistical software, version 4.1.2. This study is considered double-blind because the measurements will be performed by professionals external to the research.

The investigators estimate the participation of 144 children residing in the Maule region, Chile who meet the following inclusion criteria: (i) be enrolled in the educational center (school, college or kindergarten) that commits to participate in the intervention; (ii) age range between 3 to 6 years old; (iii) attend ≥ 85% of the sessions scheduled for the combined movement and storytelling intervention (CMSI). As for the exclusion criteria, will be the following: (i) children with musculoskeletal injuries or medical contraindications (i.e., congenital heart disease, fever, diarrhea or general malaise) that would prevent their normal performance in the assessments and intervention and; (ii) children with permanent educational needs mentioned in Decree Nº83 of the Chilean Ministry of Education, such as, visual, hearing, intellectual or multiple disabilities, dysphasia or autistic disorder.

The current protocol has been reviewed and approved by the Scientific Ethics Committee of the Universidad Católica del Maule, Chile (approval number: N°105/2021, 04 August 2021) and developed following the Declaration of Helsinki for work with human beings.