The effect of strengthening and balance exercises on static stability indices in women with knee osteoarthritis (a randomized clinical trial)

Objective and Background: Knee osteoarthritis is one of the most common musculoskeletal problems that is associated with impaired balance. The objective of this study was to investigate the effect of strengthening and balance on static stability indices in female with knee osteoarthritis. Materials and Methods:  In this randomized controlled single-blind clinical trial, 13 women with knee osteoarthritis were selected using available sampling method and they were randomly assigned to two groups of strengthening exercises group and balance exercises group. Treatment program in strengthening exercises group was based on quadriceps strengthening, and in the balance exercises group, it included balance exercises. Overall stability, anterior-posterior, and medial-lateral indices were measured by Biodex Balance System in static situation at the status of open and close eyes on one and two feet before and after treatment. Treatment for both groups was performed for 3 weeks and 5 times per week. To analyze the data, independent t-test and paired t-test were used. 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 from0.87 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 involved foot at the status of close eyes reduced from9.15  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. No significant difference was found between the two groups (P>0.05). Conclusion: Significant difference was not found between groups in terms of the impact on static stability indices. However, strengthening exercises caused improvement in greater number of stability indices compared to those in the balance exercises group.