Popliteus and Quadriceps Muscle Thickness and Clinical Parameters in Knee Osteoarthritis

Primary outcomes

1. Ultrasound measurement of popliteus and quadriceps muscle thickness

   Time frame: Baseline (single assessment visit)

   Popliteus and quadriceps (rectus femoris + vastus intermedius) muscle thickness will be measured via B-mode ultrasonography using a high-frequency linear probe (10-15 MHz), with three measurements averaged per muscle. The correlation between mean popliteus and mean quadriceps thickness (mm) will be assessed using Pearson or Spearman correlation coefficients, depending on data distribution.

2. Timed Up and Go Test (TUG):

   Time frame: baseline

   The participant sits on a standard armless chair (43-46 cm height); upon the "start" command, they stand up, walk a marked 3-meter distance, turn, walk back to the chair, and sit down. The time elapsed from the start command until the participant sits down is recorded in seconds. The individual wears comfortable footwear, walks at a normal walking speed, and any standard assistive devices (e.g., cane) used are noted

3. 5-Times Sit-to-Stand Test (5STS)

   Time frame: Baseline

   It is a reliable test used to assess sitting and standing ability. In older adults, it evaluates functional mobility, lower extremity muscle strength, and balance (19). The participant crosses their arms over their chest, and the time required to complete 5 consecutive sit-to-stand repetitions is measured.

4. Knee Injury and Osteoarthritis Outcome Score (KOOS)

   Time frame: Baseline

   KOOS is a comprehensive and reliable instrument for knee injuries and knee osteoarthritis. The scale consists of 5 subscales: Pain (9 items), Other Symptoms (7 items), Function in Daily Living (ADL) (17 items), Sport/Recreation Function (5 items), and Knee-Related Quality of Life (4 items). Each subscale is normalized to a score of 0-100, where 100 indicates no problems and 0 indicates extreme problems

5. Romberg Test

   Time frame: Baseline

   The patient is asked to stand upright with their feet together and arms hanging freely at their sides.The patient must wear hard, thin-soled shoes during this test. Without receiving any support, the patient is asked to stand first with eyes open and then with eyes closed. Safety precautions must be taken during this test to prevent falls; the examiner must remain close to the patient at all times and be prepared to catch them if they fall. In peripheral vestibular pathologies, the direction of sway/fall is toward the side of the lesion

6. Visual Analog Scale (VAS)

   Time frame: Baseline

   Participants will be asked to mark their average perceived pain intensity on a 10-centimeter (cm) line (defined as 0 = no pain, 10 = unbearable pain) during rest, activity, and sleep. Baseline pain scores will be obtained by measuring the distance between the marked point and the zero point using a ruler

7. Standardized Mini-Mental State Examination (SMMSE)

   Time frame: Baseline

   Developed by Folstein et al. in 1975 to assess cognitive status in adults. Its validity and reliability for the Turkish population were conducted by Güngen et al. A modified version is also available for individuals with less than five years of education. SMMSE is categorized under five main headings: orientation (10 points), registration/memory (3 points), attention and calculation (5 points), recall (3 points), and language (9 points). The scale is evaluated out of a total of 30 points. In scoring: results between 24 and 30 points indicate "normal" cognitive status, 18 to 23 points indicate "mild dementia," 12 to 17 points indicate "moderate dementia," and scores below 12 indicate "severe dementia" (Güngen et al., 2002). Individuals scoring 24 and above on the SMMSE were included in our study.