The impact of early intervention on early spontaneous movements of infants: a systematic review

Background: Early intervention in infants can impact the process of neural differentiation during the period when the brain is highly plastic. However, it is unclear whether early intervention can similarly affect early spontaneous movements of infants. Aim: To determine the effects of early intervention approaches on early spontaneous movements in infants. Methods: Studies were eligible if they enrolled infants in any early intervention program and assessed early spontaneous movements using a general movements assessment pre- and post-intervention. Five databases were searched and the PRISMA guideline was followed. The Cochrane Risk of Bias Tool-2 and the Risk of Bias in Non-randomized Studies of Interventions were used to identify risk of bias. GRADE approach was used to assess the certainty of the evidence. Results: Ten studies (involving 633 participants) were included. Most of the studies had a high or serious risk of bias, and the certainty of the evidence was low to very low. The studies varied in their intervention approaches, intensity, and inclusion criteria. The most common early intervention methods were motor interventions, such as physiotherapy, or parental involvement. In four out of five studies which showed an improvement, this improvement occurred during the fidgety period. Conclusions: Early intervention in infants could influence the spontaneous movements, particularly during the fidgety period. The generalizability and comparability of the results are limited due to the heterogeneity of the methods, the low certainty of evidence and the high risk of bias. Future research should investigate the impact of high-level evidence approaches on early spontaneous movements.