Examination of Gait Asymmetry During Walking With Additional Arm Weights

Gait symmetry is often assumed in healthy individuals, yet functional asymmetries arise from biomechanical and neurophysiological factors. Although light upper body loading can improve walking performance, its effect on lower limb joint asymmetry remains unclear. This study examined how different loading conditions affect sagittal plane gait asymmetry at the hip, knee, and ankle. Twenty-two participants walked under 4 conditions: no weight, unilateral arm weight, bilateral arm weights, and waist weights each using 0.45-kg loads. Three-dimensional joint angles were normalized to 101 points across the gait cycle. Asymmetry was assessed using statistical parametric mapping and pointwise effect size. Two metrics were used: (1) temporal extent, defined as the percentage of the gait cycle with significant left-right differences (P < .05) and the percentage of the gait cycle with effect size >0.8 and (2) group-level prevalence, defined as the percentage of participants showing significant asymmetry at each time point. Significant asymmetries were observed across all joints and conditions, with hip and knee levels consistently exceeding those at the ankle. Effect size values often exceeded statistical thresholds, highlighting meaningful differences. Loading produced minimal systematic effects, though individual responses varied. Importantly, light arm weights did not increase asymmetry, supporting their use for gait enhancement.