Ground reaction force analysis of the young and elderly gait on the influence of the overweight simulation

Abstract

The aim of this study was to evaluate the ground reaction forces (FRS) in young and old individuals under the influence of simulated overweightin differents gait speeds. Method: 30 participants, 15 young (YNG; 22±3.7 years) and 15 older adults (OA; 69.8±6.4 years) walked on a walkway with and without an additional load. The simulation of overweight occurred through the addition of load in a variable load vest until reaching the body mass index (BMI) of overweight (BMI YNG 25kg/m2; OA 27kg/m2). FRS were measured using an force platform (AMTI, OR6-7-2000). Results: The mean load to produce an overwight status was 13.2 ± 4.0 kg for young and 11.7 ± 3.4 kg for older adults. The significant level adopted was p≥0,05. When normalizing by body weight, the OA presented lower FRS peaks in comparison to YNG group at both speeds. On the other hand, the OA presented higher second peak of the vertical force (Fz2) in the fast speed condition in comparison to the YNG. Conclusion: Directly simulated overweight may not be able to promote significant changes in the unload quantities, arising from bodyweight, that may influence the FRS.