Knee osteoarthritis is one of the most common musculoskeletal problems that is associated with impaired balance. This study was conducted to determine the result of balance and strengthening training in static stability indices in females with knee osteoarthritis. Methods: In this single-blind randomized controlled study, 13 patients were determined through the available sampling method and randomly assigned to strengthening exercises and balance exercises groups. Strengthening exercises were based on quadriceps strengthening and in the balance exercises group, it included balance exercises. Anteriorposterior, overall, and medial-lateral stability measures were performed by Biodex before and after the treatment in the static situation at the status of open and close eyes on one and two feet. The treatment was performed 15 sessions for 3 weeks. The data were analyzed by paired t-test and independent t-test. Results: In strengthening exercises group, at the static status, overall and anterior-posterior stability index on two feet at the status of open eyes reduced from 1.26±0.82 to 0.76±0.48 (P=0.02) and from 0.87±0.53 to 0.56±0.37 (P=0.02), respectively. In the balance exercise group, in the static status, overall lateral stability index on the involved foot at the status of close eyes reduced from 9.15±3.18 to 7.53±2.81 (P=0.00) and from 8.27±3.32 to 6.77±2.95 (P=0.00), respectively. There was no significant difference between the groups (P>0.05). Discussion: There was no difference between them regarding the impact on static stability indices. However, strengthening exercises caused improvement in the greater number of stability indices compared to those in the balance exercises group.

Background and Objectives: One of the predisposing factors for postural sway changes in patients with knee osteoarthritis is the severity of knee pain. Therefore, the purpose of this study was to evaluate the relationship between pain severity and static and dynamic balance indices in patients with knee osteoarthritis.Materials and Methods: 15 patients with knee osteoarthritis were selected through simple non-probability sampling. Static and dynamic balance indices were also measured by Biodex system, the pain severity by the Visual Analogue Scale (VAS) in two pre and post time intervals. The treatment was performed for the balance trainings group for 3 weeks and 5 times per week. Paired statistical t-test and Pearson test were used to analyze the data.Results: The results showed that balance trainings resulted in significant improvement in pain severity and dynamic and static balance indices. There was a significant direct correlation between pain severity and anterior-posterior stability index and medial-lateral stability index on two feet with the closed eyes with exercise, respectively (rho = 0.52, p = 0.04) and (rho = 0.53, p = 0.03). There was also a significant indirect correlation between pain severity and anterior-posterior stability index on the affected leg with the closed eyes (rho = 0.60, p = 0.01).Conclusion: The results of the study confirm the direct and indirect relationship between dynamic balance indices and pain intensity; in the future studies the effect of pain on neuromuscular factors should be considered.