Effectiveness of knee extensor biofeedback training on pain, quadriceps muscle power and activities of daily living in patients with primary knee osteoarthritis

Abstract

Background: Primary knee osteoarthritis is a common degenerative joint condition associated with pain, quadriceps muscle weakness, and functional limitations. Arthrogenic muscle inhibition reduces voluntary quadriceps activation, limiting the effectiveness of conventional strengthening exercises. Electromyographic biofeedback has emerged as a promising intervention to enhance neuromuscular activation and improve muscle performance. Objective: To evaluate the effectiveness of knee extensor biofeedback training on pain, quadriceps muscle power, and activities of daily living in patients with primary knee osteoarthritis. Methods: A quasi-experimental study was conducted among 10 participants diagnosed with primary knee osteoarthritis. Pain was assessed using the Visual Analogue Scale (VAS), quadriceps muscle power using a handheld dynamometer, and activities of daily living using the KOOS-12 questionnaire. Participants underwent knee extensor strengthening using EMG biofeedback combined with conventional physiotherapy for 4 weeks. Pre- and post-intervention data were analysed using paired t-test. Results: There was a statistically significant reduction in pain (pre: 6.70 ± 0.82; post: 3.40 ± 0.97; t = 8.34, p < 0.001), significant improvement in quadriceps muscle power (pre: 5.77 ± 1.75 kg; post: 7.33 ± 1.54 kg; t = 7.07, p < 0.001), and significant improvement in KOOS-12 scores (pre: 48.40 ± 5.87; post: 64.30 ± 7.92; t = 22.51, p < 0.001). Conclusion: Knee extensor biofeedback training combined with conventional physiotherapy is effective in reducing pain, improving quadriceps muscle power, and enhancing activities of daily living in patients with primary knee osteoarthritis.