The control group will be followed up with a home exercise program, and notes will be taken.

It consists of 74 items covering various health domains, including physical functioning, emotional well-being, and general symptoms. The items are divided into four dimensions related to the child's quality of life: gross motor function (GMF), fine motor function (FMF), psychosocial function (PF), and systemic or general symptoms (SGS). Each domain is scored on a Likert-type scale from 1 to 7, with higher scores indicating poorer health-related quality of life. There is also a "not applicable to me" option for the items. The scale also includes a pain measurement (10 cm Visual Analog Scale (VAS)) to assess pain, but this score is not included in the total score.

It is a 20-question survey that assesses children's and adolescents' community participation in school, neighborhood, and local settings. The survey is divided into four sections: 6 questions about home participation, four questions about neighborhood and community involvement, five questions about school participation, and five questions about home and community engagement. It is rated on a scale of "expected for their age (full participation), somewhat limited, very limited, unable to participate, and inapplicable." The survey is completed by the child's family or primary caregiver. The person filling out the questionnaire is asked to select the answer that best describes the child's level of participation. The assessment is scored out of 100 points, with higher scores indicating greater participation.

JAB-Q is a multidimensional questionnaire and a parent (family) form. Developed in Turkish by Ünal and colleagues, the questionnaire is completed by one of the child's parents. The family form evaluates the parents' biopsychosocial status from their own perspective and provides scores ranging from 0 to 102. Higher scores indicate a worse biopsychosocial status.

It is used to evaluate swallowing disorders in pediatric patients. It was developed as the pediatric version of the EAT-10, which is used in adults. The PEDI-EAT-10 comprises 10 questions, each with a Likert scale ranging from 0 to 4 (0 = no problem, 4 = severe problem). The total score is calculated out of 40 points.

It is assessed using a 5-point Likert scale ranging from 0 (never) to 4 (always) and consists of 13 items. Similar to the child questionnaire, it assesses 3 domains: rumination, magnification, and helplessness. A total score between 0 and 52 is obtained; higher scores reflect a higher level of catastrophizing in parents.

It was developed by adding five questions to the HAQ regarding Raynaud's phenomenon, digital ulcers, gastrointestinal, pulmonary, and general scleroderma symptoms, to be rated on a 15 cm line. The SHAQ total score ranges from 0 to 3. A high score indicates low functionality.

It will be used to determine an individual's quality-of-life level. Each sub-parameter is scored between 0 and 100, with higher scores indicating better health status. The SF-36 scale has eight sub-parameters: general health perception, physical function, social function, pain, mental health, role difficulty due to physical reasons, role difficulty due to emotional reasons, and vitality. It contains 11 questions, each with 36 items.

It is a questionnaire consisting of 10 questions with a Likert scale ranging from 0 to 4 (0 = no problem, 4 = severe problem). The total score is calculated out of 40 points by summing the responses given to each question. A score of 3 or higher is considered abnormal in the questionnaire.

Individuals' knee muscle strength will be assessed using the Biodex System 3 Pro® isokinetic device (Biodex Medical Systems Inc., Shirley, NY, USA), which is routinely used at Hacettepe University, Faculty of Medicine, Department of Sports Medicine. Before each assessment, participants will perform a 10-minute warm-up walk and then undergo maximal concentric isokinetic muscle strength tests of the knee flexors and extensors at angular velocities of 180°/s (10 repetitions) and 60°/s (5 repetitions), with 30-second rest intervals. Peak torque (PT) and average power (AP) will be recorded in newton-meters (Nm) and watts (W), respectively. Participants will be informed in advance of how to perform maximum-power training, and verbal encouragement will be provided during the tests.

Hand grip strength will be evaluated using the Jamar hand dynamometer (Jamar; JLW Instruments, Chicago, IL), which is routinely used at Hacettepe University, Faculty of Medicine, Department of Sports Medicine. The test will be administered according to the American Hand Therapy Association's assessment recommendations. According to these recommendations, measurements will be taken with individuals seated in a chair without armrests, with the arm in adduction, the elbow at 90° flexion, the forearm in mid-rotation, and the wrist in a neutral position. A 15-second rest interval will be given between each measurement, and a total of three measurements will be taken. The average of the three scores will be recorded in kilograms-force.

Proprioception assessment will be performed at the wrist based on the principle of actively repeating a predetermined target angle. Measurements will be applied in all axes of movement of the wrist (flexion-extension, radial-ulnar deviation) on a surface showing a 180-degree angle range. Target angles are set at 30° for flexion-extension, 10° for radial deviation, and 15° for ulnar deviation.

Vascular assessments will be performed using Doppler ultrasound in the Department of Radiology at Hacettepe University Faculty of Medicine. Spectral Doppler ultrasonography and shear wave elastography (SWE) measurements will be performed using a 9 MHz linear probe on a Siemens Acuson S2000 device.

Doppler US measurements will be taken from the radial and posterior tibial arteries, and the Resistive Index (RI = peak systolic velocity - end-diastolic velocity/peak systolic velocity) value will be calculated. Three measurements will be taken from each artery, and the average RI value will be used.

SWE measurements will be performed on the bilateral deltoid, rectus femoris, and forearm extensor muscles. Three measurements will be taken from the medial and lateral regions of each muscle, and the average SWE value will be obtained. Before all measurements, participants will rest for at least 30 minutes, and the probe will be placed parallel to the muscle fibers.

Inflammatory markers will be collected via venipuncture during routine testing on the day of the clinical interview. Collected blood samples will be centrifuged at 2000 × g for 10 minutes and stored at -80 °C until kit analysis. Serum cytokine levels (TNF-α, IL-1, IL-6, IL-10) and serum irisin levels will be determined using ELISA kits.

It is a functional test developed specifically for scleroderma to assess an individual's hand function. It evaluates four specific hand movements (finger flexion, finger extension, finger abduction, and dorsal extension). Scores range from 0 (normal) to 3 (complete failure) for each movement, with a total score ranging from 0 to 12.

After ensuring individuals open their mouths as widely as possible, the distance between the incisal edges of the central incisors in the upper and lower jaws is measured in millimeters and recorded.

The time it takes a person to rise from a chair with back support, walk 3 meters at a normal pace, and return to the chair is measured in seconds to evaluate lower-extremity balance. The test will be performed 3 times.

To assess the subject's lower extremity strength and dynamic balance, the time taken to quickly climb and descend a staircase with 10 steps, each measuring 16-20 cm high and equipped with a handrail, is recorded in seconds. The test is repeated three times, and the times are recorded.

The individual is on a 10-meter path. The assessment is performed in three repetitions and recorded in seconds.

It is performed to evaluate lower-extremity endurance by having the individual stand up from a chair with their arms crossed over their chest, then sit back down. The individual is instructed to repeat this as quickly as possible for 30 seconds. The score for this assessment is the number of times the person fully rises from a seated position with arms crossed within 30 seconds.