RELATIONSHIP BETWEEN ULTRASONOGRAPHIC QUADRICEPS MUSCLE THICKNESS AND SARCOPENIA MARKERS (HANDGRIP STRENGTH, SARC-F) AND KINESIOPHOBIA IN STROKE PATIENTS

The aim of this study is to evaluate the relationship between ultrasonography-measured quadriceps muscle thickness and the sarcopenia markers SARC-F questionnaire and handgrip strength in patients diagnosed with ischemic stroke. In addition, the relationship between quadriceps muscle thickness and the level of kinesiophobia will be quantitatively assessed. This study is a cross-sectional clinical study conducted between August 1, 2025, and August 1, 2026, at the Physical Medicine and Rehabilitation Clinic of the University of Health Sciences İstanbul Physical Medicine and Rehabilitation Training and Research Hospital. Fifty volunteer participants with ischemic stroke and a lower-extremity Brunnstrom motor stage of 3 or higher, who presented to the clinic during the study period, were included. Bilateral quadriceps femoris muscle thickness, including the rectus femoris and vastus intermedius muscles, was measured using ultrasonography. The SARC-F questionnaire was used to assess sarcopenia risk, handgrip strength measurement was used to evaluate muscle strength, and the Tampa Scale for Kinesiophobia was used to determine the level of kinesiophobia. Motor recovery stage was assessed using the Brunnstrom Staging system; motor and cognitive independence were assessed using the Functional Independence Measure; walking independence was assessed using the Functional Ambulation Scale; and independence in activities of daily living was assessed using the Barthel Index of Activities of Daily Living. Because balance impairment, muscle weakness, and limited mobility are common after stroke, physical performance tests may be difficult to administer safely and consistently in this patient population. Therefore, the relationship between quadriceps muscle thickness and physical performance tests was not evaluated in this study. The Chair Stand Test, which requires repeated sit-to-stand movements as well as adequate balance and lower-extremity muscle strength, was also not included because it may increase the risk of falls in patients with limited mobility. This study aims to demonstrate the clinical potential of ultrasonography in the assessment of post-stroke sarcopenia and to support a more holistic approach to stroke rehabilitation planning that considers both physical and psychological factors.

Inclusion Criteria: * Chronic stroke duration between 6 months and 2 years * Ischemic stroke type * Age between 40-80 years * Brunnstrom lower extremity motor stage ≥3, ambulatory * Provision of written informed consent Exclusion Criteria: * Hemorrhagic stroke * Stroke onset more than 2 years prior * Inflammatory arthritis or other rheumatologic disease * History of knee trauma * Pre-stroke neurological gait disorder * Recurrent stroke * Lower extremity amputation * Knee joint contracture