WATERinMOTION Aquatic Therapy in Obese Men With Knee Osteoarthritis

100 participants (BMI ≥30, age 45-65, radiographic knee OA) will be randomized to: Aquatic group: 24 sessions over 8 weeks (3x/week) in 32°C water, progressing from buoyancy-assisted to resistance exercises. Land group: Matched duration/intensity land-based rehabilitation. Primary outcomes: WOMAC pain/function. Secondary outcomes: SF-36 quality of life, serum COMP, 6-minute walk test, and accelerometer-measured step count.