Gait and postural stability in obese and nonobese prepubertal boys

Objective: To examine differences in gait and postural stability of obese and nonobese prepubertal boys. Design: Percentage of gait cycle in double support was examined to determine significant differences. Postural stability was compared using temporal and frequency measures of the center of pressure in static stance. Setting: Gait was examined using videography on a 30-meter walkway. Postural stability was examined using a measurement platform. Participants: Ten obese (>95th percentile in body mass index) and 10 nonobese (15th to 90th percentile in body mass index) prepubertal boys aged 8 to 10yrs, Intervention: Participants were examined at three walking cadences as determined by preferred gait cadence. Full vision, darkness, and visually confused conditions were used to accentuate static postural stability differences. Main Outcome Measures: In the presence of dynamic stability differences (gait), static stability measures further investigated stability differences. Results: Obese boys spent significantly (p <.02) greater percentage of gait cycle in dual stance, Obese boys showed significantly (p <.01) greater sway areas, energy, and variability primarily in the medial/lateral direction. Conclusions: Dual stance differences suggest diminished dynamic stability in obese boys. Greater sway areas in medial/lateral direction in obese boys and the absence of significant frequency measures suggest that the instability observed in obese boys is caused by excess weight rather than underlying postural instability.