Purpose This study aimed to evaluate the effect of motivational interviewing (MI) and mindfulness (MF) added to neuromuscular (NM) exercises on improving pain, function, balance, and quality of life in patients with knee osteoarthritis (KOA). Methods This randomized clinical trial was conducted on sixty patients who were randomly assigned to the MI + NM, MF + NM, and NM groups. The groups received four training sessions for six weeks. Physical function with Western Ontario and McMaster Universities Arthritis Index timed up and go, going up and down eight stairs, pain with visual analogue scale, quality of life with SF36, and balance with Biodex were evaluated before and after interventions. Results Within-group comparisons showed that NM + MI, NM + MF, and NM groups experienced significant improvement in all factors after six-week (p < 0.05). However, between groups, comparisons in the post-test revealed that the MI + NM group had a more significant effect on pain, function, and static balance than the MF + NM group. Nevertheless, the MF + NM group improved the quality of life better than the MI + NM and NM groups (p < 0.05). Conclusion Adding psychological interventions to physical exercises had a better effect on improving the symptoms of patients. Additionally, the MI showed more effectiveness in improving the symptoms of patients.
