Association between Weight Change and Knee Joint Kinetics during Gait in Overweight and Obese Older Adults with Knee Osteoarthritis

Abstract

1609 INTRODUCTION: A strong relationship exists between obesity and increased prevalence and incidence of knee osteoarthritis (OA). In addition, cross-sectional studies show altered ground reaction forces and impulses in obese versus non-obese older adults with knee OA. PURPOSE: The purpose of this investigation was to determine the association between weight change and knee joint kinetics during gait in overweight and obese older adults with knee OA. METHODS: Data were obtained from a subset of participants enrolled in the Arthritis, Diet, and Activity Promotion Trial (ADAPT) who were randomly assigned to either exercise, dietary weight loss, exercise plus dietary weight loss, or healthy lifestyle interventions. One hundred fifty six sedentary, overweight or obese older adults with self-reported disability and radiographic evidence of knee OA (BMI: 34.2 +/− 0.6 kg/m2; Age: 68.6 +/− 0.6 yrs; Gender: 73% female) underwent three dimensional gait analysis at a freely-chosen walking speed using a 4-camera Motion Analysis high-speed (60 Hz) videography system, AMTI force platform (1000 Hz), and Lafayette 63501 photoelectric control system. Kinematic and kinetic data were synchronized, and knee joint forces were calculated using an inverse dynamics model. Primary gait kinetic outcome variables included knee joint forces (peak and average values of compressive and anteriorposterior forces) and internal knee joint moments (internal/external rotation, abduction/adduction, and flexion/extension moments). The results of this study will further our understanding of the potential structural abnormalities associated with overweight and obesity that may lead to knee OA.