The effects of knee brace, biomechanical footwear device, and exercise in knee osteoarthritis: a randomized clinical trial

BACKGROUND: Knee osteoarthritis (OA) poses a significant economic and personal burden globally. OBJECTIVE: To investigate the effectiveness of clinical interventions for knee OA. METHODS: This randomized clinical trial was conducted at Central Finland Central Hospital. A total of 136 participants with mild-to-moderate knee OA participated in the intervention (60% women, mean age 61 years). The primary intervention lasted 4 months, with a 12-month follow-up. Participants were allocated to: (1) knee brace plus exercise, (2) biomechanical footwear device, or (3) exercise alone. The primary outcome was knee pain intensity measured using the Visual Analog Scale (VAS, 0-100 mm). Secondary outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, stiffness, and function subscales, and health-related quality of life assessed using the Short Form 36 Health Questionnaire (SF-36) physical and mental component scores. RESULTS: Knee pain decreased at both 4 and 12 months in all groups. Mean VAS reductions at 4 and 12 months were -48 and -38 mm in the knee brace plus exercise group, -32 and -28 mm in the footwear group, and -35 and -26 mm in the exercise group. A significant between-group difference favoring the knee brace plus exercise group was observed at 4 months (P = 0.009), but not at 12 months (P = 0.067). WOMAC pain scores also showed a between-group difference at 4 months (P = 0.042), favoring the knee brace plus exercise and footwear group over exercise alone, with no difference at 12 months. SF-36 physical component change scores favored the knee brace plus exercise and footwear groups at 12 months (P = 0.003), while no between-group difference was observed for the mental component. CONCLUSIONS: All interventions reduced knee pain. Knee brace combined with exercise showed greater short-term benefit, but the difference was not clinically significant. Findings should be interpreted cautiously, and further research is needed. This clinical trial is registered on ClinicalTrial.gov with ID NCT03684850.