BIOLOGICAL MATURATION AND MUSCULAR STRENGTH: MEDIATION ANALYSIS IN PREPUBESCENT GIRLS

Abstract

ABSTRACT Introduction: Biological maturation has been related to the level of physical activity and motor competence of children. Objectives: This study aimed to: 1) analyze the association between biological maturation and performance in muscular strength tests and 2) examine whether the relationship between maturation and performance in physical tests is mediated by anthropometric variables. Method: The sample was composed of 71 eight-year-old Brazilian girls. Anthropometry considered stature, body mass, waist circumference, estimated fat mass and fat-free mass. Biological maturation was assessed based on the percentage of predicted adult stature. The physical tests consisted of 2-kg medicine ball throw, handgrip strength, sit-ups and standing long jump. Pearson’s correlation test was conducted between the study variables and the last stage consisted of a causal mediation analysis. Results: Biological maturation was significantly associated with the 2-kg medicine ball throw (r=0.52) and handgrip strength (r=0.42) tests. In the 2-kg medicine ball throw, the relationship with maturation was mediated by body mass (total mediation, Sobel’s Test = 2.214, p<0.05) and by estimated lean mass (total mediation; Sobel’s Test = 3.146, p<0.001). In the handgrip strength test, body mass was the only mediating variable (total mediation; Sobel’s Test = 2.251, p<0.05). Conclusions: Advanced maturational status appears to contribute to the performance of prepubescent girls in muscular strength tests in which there is no translocation of total or partial body mass. It is recommended that studies be conducted in other age groups. Level of Evidence III; Study of nonconsecutive patients; without consistently applied reference ‘‘gold’’ standard.