A Comparison of Lean and Obese Gait Characteristics of Children and Adults During Level Walking

Abstract

Increased body mass affects gait kinematics and kinetics in adults. It is however unknown if increased body mass produces similar adaptations in children and adults. The duration of obesity in children is shorter than in adults, thus the magnitude of adaptation to increased mass is expected to be less in obese children's gait. Alternatively, obese children and adults may have similar gait adaptations, indicating that obese gait evolves relatively rapidly after or while becoming obese and has no cumulative effect on the magnitude of gait adaptations. The purpose of this study was to compare gait kinematics and kinetics between lean and obese children and adults. Lean (age 13 ±1.6 y, BMI =18 ±1.5 kg/m2) and obese (age 13 ±1.7, BMI = 31 ±3.9) children and lean (age 36 ±4.7, BMI = 24 ±1.9) and obese (age 34 ±7.7, BMI = 48 ±8.8) adults walked at 1.5 m/s on a level surface while gait kinematics and kinetics were measured in one session. Kinematic and kinetic variables were analyzed with a 2x2 factorial analysis of variance followed by Tukey's post-hoc test. Children and adults walked with many stride characteristics, with obese individuals spending 4% more time in stance phase than swing phase compared to lean individuals. In the knee, there was an age (p = 0.046), mass (p = 0.001), and a borderline age by mass interaction effect (p = 0.053) with obese vs lean individuals producing more impulse and obese adults producing the highest impulse. In the ankle, there was an age, mass, and interaction effect (all p = 0.001) with obese producing higher impulses compared to lean and obese adults producing the highest impulse. In conclusion, the magnitude of adaptation in kinetics was similar in children and adults at the hip and ankle joint but adults' adaptation was significantly greater at the knee. It is possible that the unique neuromuscular adaptations in obese gait in children and adults are due to adults being obese for a longer time than children.