Biomechanical Analysis of Obesity-Related Changes in Gait Patterns

ABSTRACT

Obesity has not only been associated with cardiovascular and metabolic diseases but also with many musculoskeletal disorders such as knee osteoarthritis. Studies exploring the effects of obesity on gait have resulted in many inconclusive/contradicting findings. The aim of the current study was to examine the effects of severe obesity on 1) preferred walking speed (PWS), 2) spatiotemporal characteristics and 3D knee kinematics of walking at the PWS and a standard fast speed (6 kmꞏh^-1). Eight healthy male adults (four severely obese and four normal-weight (NW) aged 19 to 33 years volunteered for the study. A 3D analysis was done using a motion capture and analysis system (OptiTrack Prime 17W, NaturalPoint Inc, USA). Furthermore, a personalized MATLAB program was used to process data. t-tests were used to test for group differences in age and height and PWS. A two-way analyses of variance tested the effect of speed and group on all gait variables. Results showed no differences in PWS between groups, however obese participants presented a significantly different spatiotemporal organization of gait as well as higher variability of most spatiotemporal variables compared to normal weight participants. Knee peak joint angles in the three planes of motion at stance and swing were analyzed and significantly higher values were found for the obese group in the peak knee abduction at stance and external rotation at swing, compared to NW. Differences were mostly pronounced for obese participants in relation to the general organization and control of gait, with some changes noted at the peak knee joint angle for this young sample. Obese participants displayed less overall dynamic stability (e.g., higher CoM displacement variability) and less control over their gait. It is recommended to complement this analysis with a larger sample size to get better insights on mechanisms underlying the development of OA. Furthermore, obese individuals might benefit from knee stabilization exercises to counteract the underlying medio-lateral instability and to improve gait dynamic balance.