Effects of swimming intervention on motor competence and dynamic balance in children at risk for developmental coordination disorder: a pre-post intervention study

Background Developmental Coordination Disorder (DCD) affects approximately 5–6% of school-aged children and is characterized by significant motor skill impairments that may persist into adulthood without intervention. Aquatic-based swimming programs have been proposed as a feasible approach to support motor development in children with neurodevelopmental motor difficulties. However, evidence specifically evaluating structured swimming interventions for DCD-related motor impairments remains limited. Objective To describe pre-post changes in motor competence and dynamic balance following a structured swimming intervention in children at risk for DCD. Methods Fourteen children at risk for DCD (9 boys, 5 girls; mean age 8.25 ± 0.83 years) participated in a single-group pre-post intervention study involving a 10-week breaststroke swimming program (20 sessions, 60 min each, twice weekly). Motor competence and dynamic balance were assessed before and immediately after the intervention. Motor competence was assessed using the Movement Assessment Battery for Children-Second Edition (MABC-2), and dynamic balance was evaluated with the Y-Balance Test Lower Quarter (YBT-LQ) at the pre- and post-intervention time points. Results MABC-2 Total Test Score increased from pre- to post-intervention (median change 5.50; unadjusted p = 0.007, adjusted p = 0.021; r = 0.72), and Aiming and Catching showed a positive pre-post change (median change 25.00; unadjusted p = 0.004, adjusted p = 0.014; r = 0.77). In the YBT-LQ, five of six reach directions were higher at post-intervention than at baseline at the unadjusted level, and four directions remained significant after Holm correction, with medium-to-large effect sizes (Cohen’s dz. = 0.77–0.85). The intervention achieved a 100% retention rate with no adverse events. Conclusion In this single-group pre-post study, children at risk for DCD showed positive pre-post changes in motor competence and dynamic balance over the 10-week study period, with the clearest changes observed in overall MABC-2 performance, aiming and catching, and several YBT-LQ reach directions. These findings provide preliminary, feasibility-informed evidence under structured conditions and suggest that this intervention model may warrant further controlled evaluation. However, studies including control conditions and functional outcome measures are needed before broader practice recommendations can be made for children at risk for DCD.