Relationship Between Children's Postural Balance And Body Composition, Physical Fitness, And Daily Physical Activity

Balance plays an important role in several domains of children's lives, such as fall risk and motor competence. However, the factors that are associated with balance in children remain unclear. PURPOSE: To investigate the association of body composition, physical fitness, and daily physical activity on balance in children. METHODS: A sample of 224 children (53% females), aged 9.0 ± 1.2 years with a body mass index (BMI)-percentile of 65.0 ± 28.8 were recruited. Balance, represented by mean velocity of the center of pressure (CoP; cm·s−1), was evaluated through a force platform in the upright bipedal stance in four conditions: i) eyes open on a rigid surface (EO/RS); ii) eyes closed on a rigid surface (EC/RS); iii) eyes open on a foam surface (EO/FS); and vi) eyes closed on a foam surface (EC/FS). Anthropometry, body composition (dual-energy x-ray absorptiometry), knee maximal strength (isokinetic dynamometer), aerobic capacity (indirect calorimetry), and daily physical activity (accelerometry) were also measured. RESULTS: Participants presented higher CoP velocity (worse balance) from condition i to condition vi: 1.38 ± 0.70, 1.65 ± 0.86, 2.06 ± 0.87, and 3.36 ± 1.23 cm·s−1, respectively (p < .001 between all condition comparisons). Partial correlation, controlling for sex and age, showed that balance was associated with: relative knee extension strength (r = -0.15; p = .024) in EO/RS condition; fat mass percent (r = 0.14; p = .033) and relative knee extension strength (r = -0.18; p = .008) in EC/RS condition; body mass (r = 0.18; p = .010), BMI (r = 0.20; p = .003), fat mass index (r = 0.24; p < .001), fat mass percentage (r = 0.25; p < .001), relative knee extension strength (r = -0.20; p = .003), relative knee flexion strength (r = -0.16; p = .016), and relative peak oxygen uptake (r = -0.24; p < .001) in EO/FS condition; and relative knee extension strength (r = -0.16; p = .017) in EC/FS condition. Multiple regression analyses showed that the best explanatory model of balance performance included age, sex, and relative knee extension strength in EO/RS, EC/RS, and EC/FS conditions (r2 = 0.15 to 0.19), and age, sex, and fat mass index in the EO/FS condition (r2 = 0.24). CONCLUSION: Higher lower-limb muscular strength and lower fat mass are associated with better balance in children. USDA-ARS Projects 3092-51000-056-04A and 6026-51000-012-06S USDA-ARS Projects 3092-51000-056-04A and 6026-51000-012-06S