Osteoarthritis of the knee is a common joint disease that causes loss of balance and proprioception. Changes in the knee joint such as mechanoreceptor loss, muscle strength imbalance, muscle weakness, capsular hypertrophy, subchondral edema, and increased loss of balance and proprioception lead to an increased risk of falls. In the literature, knee osteoarthritis is repeatedly mentioned as an independent risk factor for falls, and knee osteoarthritis is associated with recurrent falls.

There are many performance-based clinical measurement tests that assess fall risk in knee osteoarthritis. Some of these tests include the timed up and walk test, the five-step sit-to-stand test, and the one-leg stand test. These tests cannot evaluate backward walking. Backward walking requires more neuromuscular control and proprioception than forward walking. The 3-meter backward walk test is a performance-based test that assesses backward walking, balance, proprioception, and neuromuscular control. The participant is asked to walk 3 meters backwards on a flat surface at the highest speed at which they feel comfortable without running. It is administered by recording the time elapsed.

The validity and reliability of the 3-meter walk back test have been previously investigated in many patient populations and healthy individuals. However, to our knowledge, there is no research on the reliability and validity of a 3-meter walk back test in knee osteoarthritis. Clinical measurement tests should be valid and reliable in the patient population to which they are applied.

The aim of this study was to examine the test-retest reliability and concurrent validity of the 3-meter backward walk test in participants with knee osteoarthritis. In addition, we aim to compare the 3-meter backward walk test scores of individuals with and without knee osteoarthritis and to examine the change in 3-meter backward walk test scores with the change in disease severity.

The data collection tools to be used in the study are the 3-meter walk back test, the timed get up and walk test, the Knee Injuries and Osteoarthritis Outcome Score, the Frail Scale, the Modified Falls Efficacy Scale, and fall history. All of these measures will be taken at the initial assessment, and the 3-meter walk back test will be repeated after 3-7 days.

We hope that our study will help physiotherapists working in this field in the clinical decision-making process by providing a valid and reliable performance test for the assessment of fall risk.

Inclusion Criteria:

• To have been diagnosed with osteoarthritis by a specialist physician according to the clinical and radiological criteria of the American College of Rheumatology.
• Be between 40 and 75 years of age.
• Being in grade 1-4 according to Kellgren-Lawrence staging.
• To participate in the study voluntarily

Exclusion Criteria:

• Having undergone surgery involving the lower extremity
• Having prosthesis or orthosis in the lower extremity
• Other neurological and cardiopulmonary diseases that may affect walking and balance Having undergone surgery or invasive treatment in the last 6 months
• Body mass index above 45
• Having severe heart disease that prevents exercise
• Having pain originating from L3 - S1

People who have diagnosed as knee osteoarthritis