Body Composition Asymmetry as a Candidate Marker of Dynamic Movement Imbalance: A Bioelectrical Impedance Analysis Study

Bioelectrical impedance analysis (BIA) provides body composition estimates that may complement conventional assessments of dynamic movement asymmetry. This cross-sectional study examined the association between the two in 50 adults aged 20–65 years. Dynamic variables were obtained from gait analysis, electromyography, and isokinetic strength testing, and left–right asymmetry was expressed as an asymmetry index (AI). Spearman correlations were evaluated with Benjamini–Hochberg correction across a pre-specified family of 42 comparisons. Eight associations survived correction, all positive, linking the AIs of leg total body water (TBWleg), intracellular water (ICWleg), and soft lean mass (SLMleg) to stance time and gait speed during dual-task walking and to ankle and knee joint torque, with correlations ranging from 0.376 to 0.476; whole-body indices showed the opposite pattern. Against a composite score derived from these variables, TBWleg AI showed the strongest association (ρ = 0.508) and, in an exploratory analysis, separated participants in the highest tertile from the remainder with an area under the curve of 0.786. These findings support further evaluation of BIA-derived leg water and lean-tissue asymmetry indices as candidate markers of dynamic movement asymmetry; the design does not establish predictive or diagnostic validity.