Prevalence of Kinesiophobia and Its Effects on Functional Capacity and Pain Severity in Patients With Primary Knee Osteoarthritis

Knee osteoarthritis (OA) is the most prevalent chronic joint disorder, characterized by progressive cartilage degeneration, abnormal remodeling of the subchondral bone, osteophyte formation, and joint pain that frequently results in disability. The knee joint is particularly vulnerable due to its weight-bearing function and high mechanical stress, making knee OA a leading cause of mobility impairment in older adults. While radiographic evaluation using the Kellgren-Lawrence (K/L) grading system remains the standard method for diagnosing and staging OA, radiographic severity does not always correlate with clinical symptoms such as pain and functional disability. This inconsistency suggests that psychosocial factors may play an important role in shaping the clinical presentation of knee OA.

Kinesiophobia, defined as an excessive and irrational fear of movement due to the anticipation of pain or re-injury, has been reported in various musculoskeletal disorders and post-surgical recovery. High levels of kinesiophobia are associated with worse pain perception, reduced functional capacity, and lower quality of life. In knee OA, the role of kinesiophobia remains controversial, with previous studies reporting inconsistent findings regarding its relationship with pain, functional limitation, and disease progression. Understanding this relationship is crucial, as addressing kinesiophobia may help to optimize rehabilitation outcomes and reduce disability in affected patients.

The present study is a prospective, cross-sectional observational study designed to assess the prevalence of kinesiophobia in patients with primary knee osteoarthritis and to examine its association with pain severity and functional status. A total of 84 patients, aged 40-85 years, with radiographically confirmed knee OA will be recruited from the Department of Physical Medicine and Rehabilitation, Ankara Training and Research Hospital. Patients with prior knee surgery, rheumatological disease, neuromuscular conditions, or systemic inflammatory disorders will be excluded.

Data collection will include demographic variables (age, sex, body mass index, occupation, comorbidities), physical examination findings (range of motion, quadriceps strength), and radiographic staging using the Kellgren-Lawrence scale. Patient-reported outcomes will be assessed using the Visual Analogue Scale (VAS) for pain, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for function, and the Tampa Scale for Kinesiophobia (TSK), which has been validated in Turkish populations. Higher scores on these measures indicate greater pain, worse functional limitation, and higher levels of kinesiophobia.

All data will be analyzed using SPSS software. Normality will be assessed using the Kolmogorov-Smirnov test. Depending on data distribution, group comparisons will be made with Student's t test or Mann-Whitney U test, and relationships between kinesiophobia, pain, and function will be explored using correlation and regression analyses. A power analysis determined that a minimum of 84 patients will be required to achieve adequate statistical power at 80%.