Tai Chi for Treating Patients with Knee Osteoarthritis: a Randomized Controlled Trial

INTERVENTION: Treatment group:Tai Chi;Control group:Attention Control; CONDITION: Knee Osteoarthritis PRIMARY OUTCOME: Western Ontario and McMaster Universities Osteoarthritis Index; SECONDARY OUTCOME: Isokinetic dynamometry;Gait and Surface electromyography test;Short Form for Quality of Life, SF‐36;Dosage of NSAIDs; INCLUSION CRITERIA: 1. Meet the diagnostic criteria of KOA set by American College of Rheumatology; 2. Male or female patients aged 40 years or older; 3. Mild to moderate radiographic medial tibiofemoral osteoarthritis (Kellgren ‐ Lawrence score from 1 to 3) in at least one knee; 4. WOMAC pain score >= 40 (visual analog version, range from 0 to 100, higher indicating more pain) on at least one of five questions; 5. Volunteer to participate in the trial and provide written informed consent form.