Objective: Pain is the the main symptom of knee osteoarthritis. Pain causes immobilisation, limitation in the range of motion (ROM) and periarticular muscle spasm through reflex inhibition. Consequently, patients develop weakness and atrophy in the quadriceps muscle. In this study, the effect of isometric exercises and electrical stimulation was compared on patients with knee osteoarthritis. 
 

Materials and Methods: Thirty-eight patients were separated into two groups randomly. In the first group; the combination of paracetamol + infrared + electrical stimulation (20 times, once a day) treatment was applied. In the second group; the combination of paracetamol + infrared + active resistive isometric exercises (20 times, once a day) treatment was applied. The evaluations performed include pre and post-treatment pain, active ROM, thigh circumference measurements, activity time and WOMAC and Lequesne indices. Cross-sections of rectus femoris muscle were measured quantitatively by computerized tomography before and after the treatment. Clinical and radiological findings were evaluated for both groups.
 

Results: Statistically a significant improvement was observed in all of the parameters for both of the groups (p<0.05). The improvement in ROM was found larger in the exercise group in comparative group analysis (p<0.05). The diameter of the rectus femoris muscle increased in both of the groups (p<0.05). The increase in the diameter of the rectus femoris was higher in the electrical stimulation group (p<0.05). 
 

Conclusion: The treatment of electrical stimulation was found to be as efficient as the exercise treatment in cases such as knee osteoarthritis, quadriceps muscle weakness and atrophy prevention. Electrical stimulation treatment could be used alone or in combination with exercise treatment in clinical setting. And, isometric exercises could be undertaken as a home program.