Knee osteoarthritis (OA) poses a significant economic and personal burden globally.

To investigate the effectiveness of clinical interventions for knee OA.

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.

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.

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.