Validity of segmental bioelectrical impedance analysis for estimating fat-free mass in children including overweight individuals.

This study examined the validity of segmental bioelectrical impedance (BI) analysis for predicting the fat-free masses (FFMs) of whole-body and body segments in children including overweight individuals. The FFM and impedance (Z) values of arms, trunk, legs, and whole body were determined using a dual-energy X-ray absorptiometry and segmental BI analyses, respectively, in 149 boys and girls aged 6 to 12 years, who were divided into model-development (n = 74), cross-validation (n = 35), and overweight (n = 40) groups. Simple regression analysis was applied to (length)/Z (BI index) for each of the whole-body and 3 segments to develop the prediction equations of the measured FFM of the related body part.

Factors that determine directional constraint in ipsilateral hand-foot coordinated movements.

In performing simultaneous rhythmic movements of the ipsilateral hand and foot, there are differences in the level of stability between same directional (stable) and opposite directional (unstable) movements. This is the directional constraint. In this study, we investigated three factors ("interaction in efferent process," "interaction of afferent signals," and "error correction") proposed to underlie for the directional constraint.