Grip strength is considered an indicator of upper extremity muscle strength. Measurements will be recorded by testing the dominant and non-dominant hand three times using the JAMAR hand dynamometer. This device is a widely used and highly reliable grip strength measurement tool. The test will be performed in a sitting position, with the upper arm parallel to the body, the elbow flexed at 90 degrees, and the forearm and hand in a neutral position.

In our study, an algometer device will be used to assess tender points. The algometer device is a reliable device that can be used to assess tender points. Eighteen tender points will be assessed according to the American College of Rheumatology criteria for the classification of fibromyalgia. They will be marked with a pen before use. The tender points to be marked are: occipital, lower cervical, trapezius, supraspinatus, second rib, lateral epicondyle, gluteal, greater trochanter, and knees. Pain assessment will be performed by applying a vertical pressure of approximately 1 kg/s to the tender points with the algometer, and the person will be asked to report when the pressure becomes painful. A high algometer score indicates low pain

The New York Posture Assessment is a valid and reliable assessment used in posture evaluation. Posture is assessed from the lateral and posterior views. It includes a series of three-digit drawings for each of the 13 body alignment sections. These are scored as 5 (correct posture), 3 (mild deviation), or 1 (significant deviation). The highest score is 65, and the lowest is 13. A score ≥45 is "excellent," 40-44 is "good," 30-39 is "moderate," 20-29 is "poor," and ≤19 is "very poor"

A study by Ediz and colleagues demonstrated that the Turkish version of the Revised Fibromyalgia Impact Questionnaire is a reliable and valid tool. It is a self-reported questionnaire that measures functional capacity and disease severity in patients with fibromyalgia. It is an easy and short questionnaire. It consists of 3 sections with 21 questions on function, overall impact, and symptoms. It concerns experiences in the last 7 days and is scored using an 11-point numerical rating scale. The total score for the function domain (range 0 to 90, divided by 3), the global impact domain score (range 0 to 20), and the symptoms domain score (range 0 to 100, divided by 2)

Smets et al. developed the Multidimensional Fatigue Inventory-20 (MFI-20), which consists of five fatigue subscales: general fatigue, physical fatigue, mental fatigue, decreased motivation, and decreased activity. It has been used in various descriptive and experimental studies of many different diseases, including fibromyalgia. Özilhan et al.'s study demonstrated that the Turkish oncology version of the MFI-20 is a valid and reliable measure of fatigue in cancer patients, while Başoğlu et al.'s study demonstrated that it is a valid and reliable measure of fatigue in patients with multidimensional FM. When completing the scale, individuals are asked to select the degree closest to themselves, ranging from "no, not true" to "yes, very true." It consists of 20 questions. A high score indicates severe fatigue.

This is a scale that evaluates patients' social participation, daily life, and work life over the past four weeks. The questionnaire consists of 27 items. The first 16 items relate to daily life, and the following 6 items focus on the patients' social lives. Item 23 asks patients whether they are currently employed, and they can answer with "yes" or "no". Patients who answer "yes" are then asked about the level of difficulty they experience in their work life on five separate items. Patients are allowed to rate these levels on a scale of 1 to 5. The total score is calculated as the sum of the first 22 items for patients who are not employed, and as the sum of all 27 items for patients who are employed. The minimum score for those who are not employed is 22, and the maximum score is 110; for those who are employed, the minimum score is 27, and the maximum score is 135. A higher score indicates a more severe impairment (restriction).

This is a self-administered questionnaire used to assess the patient's feelings and thoughts about pain. It was developed by Sullivan and colleagues in 1995. It is a reliable and valid Turkish-language questionnaire that assesses specific variables such as severe pain, disability, and emotional distress following trauma or tissue damage. It consists of the subscales "helplessness" (inability to cope effectively with pain), 'magnification' (dissatisfaction caused by excessive focus on the negative consequences of pain), and "rumination" (inability to stop thinking about pain). It consists of 13 items and is scored on a scale of 0 to 4. It is a 52-point scale.

Participants in our study will be assessed for kinesiophobia, or fear of movement/re-injury, using the Tampa Kinesiophobia Scale, whose test-retest reliability in Turkish has been demonstrated by Tunca Yılmaz and colleagues. The scale was first developed in 1991 but was not published. It was published by Vlaeyen and colleagues in 1995. The scale covers work-related activities, injury/re-injury, and fear-avoidance. It consists of 17 questions. It is scored as follows: Strongly disagree 1, Disagree 2, Agree 3, Strongly agree 4. It is scored between 17 and 68. The higher the score, the higher the fear of movement.

It consists of 14 questions in total, 7 of which assess anxiety, 7 assess depression, and the odd-numbered questions assess anxiety symptoms while the even-numbered questions assess depression symptoms. Each question is scored between 0 and 3. Higher scores indicate higher levels of anxiety and depression.

The Morningness-Eveningness Questionnaire was developed by Horne and Ostberg in 1976 to behaviorally assess individuals' circadian rhythms and interpersonal biological rhythm variations [39]. It is the most commonly used measure for assessing chronotype preference.It consists of 19 self-assessment items, and scores are calculated according to five chronotype categories. A high score indicates a strong morning preference.

It is a commonly used measure for assessing physical activity. In our study, the 7-item International Physical Activity Questionnaire Short Form will be used.The number of days and duration of vigorous physical activity, moderate physical activity, and walking activities lasting at least 10 minutes or longer in the past 7 days are assessed. The number of days and minutes are calculated by multiplying each activity's MET value. Vigorous physical activities are calculated as 8 MET, moderate physical activities as 4 MET, and walking as 3.3 MET. Time spent sitting is not included in the scoring. All are added together for the overall physical activity score. A weekly MET value below 600 is considered inactive, 601-3,000 is moderately active, and above 3,000 is active.

This is a questionnaire consisting of 24 questions that assesses individuals' sleep quality and sleep disorders.The first 19 questions are answered by the individual themselves, while the last 5 questions are to be answered by their spouse or roommate. The last 5 questions are not included when calculating the total score. A high score indicates poor sleep quality. The first 19 questions assess a wide range of factors to estimate sleep duration, sleep onset latency, and the frequency and severity of sleep-related problems. It consists of a total of 7 subheadings: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disorders, use of sleep medications, and daytime dysfunction. Each subheading is scored from 0 to 3 and has its own calculation method. The total score ranges from 0 to 21. A score of 5 or above indicates poor sleep quality .