Age and sex differences in human balance performance from 6-18 years of age: A systematic review and meta-analysis

Background The process of growing leads to inter-individual differences in the timing of growth, maturational, and developmental processes during childhood and adolescence, also affecting balance performance in youth. However, differences in balance performance by age and sex in youth have not been systematically investigated yet. Objective The objective of the present study was to characterize and quantify age- and sex-related differences in balance performance in healthy youth. Methods A computerized systematic literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus. To be applicable for analysis, studies had to report at least one measure of static steady-state, dynamic steady-state, proactive or reactive balance in healthy children (6-12 years) and/or adolescents (13-18 years). Coding of the studies was done according to the following criteria: age, sex, and balance outcome. Study quality was assessed using the Appraisal tool for Cross-Sectional Studies. Weighted standardized mean differences were calculated and classified according to their magnitude. Results Twenty-one studies examined age-related differences in balance performance. A large effect for measures of static steady-state balance (SMDba = 1.20) and small effects for proxies of dynamic steady-state (SMDba = 0.26) and proactive balance (SMDba = 0.28) were found; all in favor of adolescents. Twenty-five studies investigated sex-related differences in balance performance. A small-sized effect was observed for static steady-state balance (SMDbs = 0.33) in favor of girls and for dynamic steady-state (SMDbs -0.02) and proactive balance (SMDbs = -0.15) in favor of boys. Due to a lack of studies, no analysis for measures of reactive balance was performed. Conclusions Our systematic review and meta-analysis revealed better balance performances in adolescents compared to children, irrespective of the measure considered. Sex-related differences were inconsistent. These findings may have implications for example in terms of trainability of balance in youth that should be investigated in future studies.