Knee osteoarthritis (OA) is a highly prevalent global health problem and associated with pain and functional disability during physical tasks and activities mainly in women

This current study helped to explore the impacts of widely seen demographic, pathological, psychological, and impairment factors on physical functioning in women with knee OA using the performance-based and self-reported measures.

This study included 110 women suffering from knee OA. There were 3 Performance-based measures:
1) 10-m walk test;

2) Timed up and go (TUG) test;

3) A stair test for the participants.

Western Ontario and McMasters Universities OA Index were used to measure self-reported physical functioning. Other measurements included were Knee muscle strength, pain intensity, flexion range of motion (ROM), body mass index (BMI), radiographic severity, and anxious and depressive symptoms. Age, disease duration, and comorbidities were also recorded. Correlation and linear regression analyses were used to assess the associations.

The findings of the study showed that in the linear regression models, knee muscle weakness, limited knee flexion ROM, pain intensity, and older age contributed to 65% of the variance in physical performance measures mostly explained by knee muscle weakness. Knee pain intensity, BMI, anxiety, and knee muscle weakness contributed to 60% of the variance in WOMAC physical function score mostly explained by pain. Radiologic severity, depression, comorbidities, and disease duration showed no significant association (P < 0.05). It was found that performance-based measures had significant but moderate correlations with WOMAC physical function score (r range 0.51-0.57, P < 0.05).

Therefore, the study concludes that in knee OA suffering women, knee muscle strength was the key determinant of performance-based physical functioning together with knee flexion ROM, knee pain, and age. Knee pain was measured as the main determinant of self-reported physical functioning. BMI, anxiety, and knee muscle strength also showed some contributions. Performance-based and self-reported measures had moderate relations and evaluated different aspects of physical functioning. For managing knee OA of women, priority should be given to the strengthening of weak knee muscles, improving limited flexion ROM, pain management, weight loss, and improving anxiety. The performance-based and self-reported measures should be used together for a comprehensive evaluation of physical functioning.