Background: The effect of exercise on knee osteoarthritis (OA) is often evaluated with patient-reported scales. The Minimal Clinically Important Difference (MCID) values of these scales are needed to understand the change in patients after treatment and to manage the treatment.

It is also one of the most important data in calculating the MCID sample size. Aim: In the literature, MCID studies for exercise applied to knee OA are limited especially for those who did not undergo surgery. Thus new studies are needed.

Method: 100 patients who were diagnosed with knee osteoarthritis will be recruited for the study. Participants will be included in an exercise program tailored to their needs for 15 sessions. WOMAC, OKS, LEFS scales will be used also knee range of motion will be assessed in the baseline, after treatments and in the 4th month follow up.

Inclusion Criteria:

• To be diagnosed with knee OA according to the criteria of the American Society of Rheumatology (ACR) (Diagnosis of primary knee OA)
• Stage 2 or 3 according to Kellgren Lawrence radiological staging criteria
• Participants with age between 50 and 70 years old
• Being able to walk without using an assistive device
• Having a body mass index of less than 30 kg/m²
• Pain severity is between 3 and 7 according to the Numerical Pain Rating Scale

Exclusion Criteria:

• Patients who received physical therapy or intra-articular injections in the last 6 months
• Receiving an indication for surgery
• Have severe hearing, vision and speech impairment
• Having serious systemic and cardiovascular diseases that interfere with exercise
• Having a lower extremity deformity
• Patients with acute inflammation of the knee