RESUMO
OBJECTIVE: To investigate the effects of squat exercises combined with whole-body vibration on the plasma concentration of inflammatory markers and the functional performance of elderly individuals with knee osteoarthritis (OA). DESIGN: Clinical, prospective, randomized, single-blinded study. SETTING: Exercise physiology laboratory. PARTICIPANTS: Elderly subjects with knee OA (N=32) were divided into 3 groups: (1) squat exercises on a vibratory platform (platform group, n=11); (2) squat exercises without vibration (squat group, n=10); and (3) the control group (n=11). INTERVENTIONS: The structured program of squat exercises in the platform and squat groups was conducted 3 times per week, on alternate days, for 12 weeks. MAIN OUTCOME MEASURES: Plasma soluble tumor necrosis factor-α receptors 1 (sTNFR1) and 2 (sTNFR2) were measured using immunoassays (the enzyme-linked immunosorbent assay method). The Western Ontario and McMaster Universities Osteoarthritis Index questionnaire was used to evaluate self-reported physical function, pain, and stiffness. The 6-minute walk test, the Berg Balance Scale, and gait speed were used to evaluate physical function. RESULTS: In the platform group, there were significant reductions in the plasma concentrations of the inflammatory markers sTNFR1 and sTNFR2 (P<.001 and P<.05, respectively) and self-reported pain (P<.05) compared with the control group, and there was an increase in balance (P<.05) and speed and distance walked (P<.05 and P<.001, respectively). In addition, the platform group walked faster than the squat group (P<.01). CONCLUSIONS: The results suggest that whole-body vibration training improves self-perception of pain, balance, gait quality, and inflammatory markers in elderly subjects with knee OA.