Neurodevelopmental Profile of Randomized Participants 
Abbreviation: MABC-2, Movement Assessment Battery for Children, 2nd Edition.Effect size measures the size of the difference between the 2 groups. A positive value reflects a positive effect on the score and a negative value, a negative effect on the score in the intervention group. According to Cohen criteria, effect sizes could be categorized as small (0.2), medium (0.5), or large (≥0.8).Children who benefitted from any of the following school assistance: special needs teaching assistant, assistance by any other professional, technical aid, personalized educational plans for children with disabilities, and other types of support. Data were missing for 20 participants (12%).Children who, in the 12 months before inclusion in the study, were followed up at a specialist center (Early Medical-Social Action Centers and Medical Psychologic Centers of Early Childhood) or benefited from 1 or more medical consultations by the following professionals: psychologist, psychometrician, orthoptist, speech therapist, and/or physiotherapist. Data were missing for 21 participants (12%).The participants randomized to the intervention group completed a mean (SD) of 18.1 (9.1) training sessions. Among them, 57 children (68%) completed 15 or more sessions, 52 (62%) completed 20 or more sessions, and 43 (51%) completed 25 sessions, with mean (SD) progression index scores of 23.4 (6.4), 23.8 (6.3), and 24.0 (6.3), respectively. The workforce’s power was reduced to 32% at 15 sessions, 38% at 20 sessions, and 49% at 25 sessions (eTable 3 in 