Transitioning from a sitting to a standing position is a movement essential for maintaining physical independence and functional mobility, and is necessary for performing many activities in daily life. Lower extremity muscle strength is considered the most critical factor reducing the capacity to perform the sit-to-stand movement. A study concluded that the Five-Times Sit-to-Stand test in patients with multiple sclerosis (MS) is multifactorial and is associated with walking speed and fatigue. Another study using the same test concluded that lower extremity capacity is reduced compared to healthy controls and is associated with balance, functional mobility, gait, and fatigue.

Pediatric-onset MS, occurring in patients under the age of 18, accounts for approximately 3-10% of all multiple sclerosis cases and is increasingly recognized in many parts of the world. According to our research, no studies have been found that demonstrate the extent of lower extremity involvement in patients with pediatric-onset MS compared to their healthy controls. Our aim is to evaluate the performance of the Five-Times Sit-to-Stand test in patients with pediatric-onset MS, compare it with healthy controls, and examine its relationship with physical activity, exercise capacity, functional mobility, quality of life and fatigue.

In addition to visual, sensory, motor, and coordination impairments, cognitive problems, pain, and fatigue may occur in patients with pediatric-onset MS. Studies have reported that patients with pediatric-onset MS tend to participate in less physical activity and have lower exercise capacity compared to their healthy peers. Lower extremity functional capacity is impaired in most patients with MS, and the high prevalence of walking disorders is an example of this. Therefore, assessing lower extremity capacity and identifying modifiable determinants appears to be important. Moreover, a detailed assessment of lower extremity parameters in MS patients is crucial for determining appropriate rehabilitation programs. Transitioning from a sitting to a standing position is necessary for performing many activities in daily life. Assessment of lower extremity muscle strength using the sit-to-stand movement enables the development of preventive interventions in the early stages of the disease.

Our aim is to evaluate the performance of the Five-Times Sit-to-Stand (FTSTS) test in patients with pediatric-onset MS, compare it with healthy controls, and examine its relationship with physical activity, exercise capacity, functional mobility, quality of life, and fatigue. Under the supervision of a physical therapist, participants will be assessed using the FTSTS test to evaluate lower extremity muscle strength, the Godin Leisure Time Exercise Questionnaire (GLTEQ) for physical activity, the 2-Minute Walk Test (2MWT) for exercise capacity, the Timed Up and Go (TUG) Test for functional mobility, the Pediatric Quality of Life Inventory (PedsQL) for quality of life, and the PedsQL Multidimensional Fatigue Scale for fatigue.

It is planned to include 30 patients with pediatric-onset MS and 16 healthy controls, making a total of 46 participants in this study. The Shapiro-Wilk test will be employed to assess whether the data adhere to a normal distribution. Differences between groups will be analyzed using the independent sample t-test for normally distributed variables and the Mann-Whitney U test for non-normally distributed variables. The Chi-square test will be used to compare categorical variables. Intercorrelations among FTSTS and other variables will be calculated using Pearson or Spearman correlation analysis. This will be the first study to evaluate the performance of the FTSTS test in patients with pediatric-onset MS.

Inclusion Criteria:

• Volunteer to participate
• Being diagnosed with pediatric onset multiple sclerosis
• Being between the ages of 15-22
• EDSS ≤6

Exclusion Criteria:

• Having another diagnosis in addition to the diagnosis of pediatric-onset multiple sclerosis
• Having had an attack or received corticosteroid treatment 3 months before participating in the study

The sample size was calculated based on the total fatigue scores in patients with pediatric-onset MS and healthy controls of the same age group, using the child form of the PedsQL Multidimensional Fatigue Scale as employed by Gravesande et al., with a 0.05 margin of error and 80% power. According to this calculation, it was seen that 25 patients with pediatric-onset MS and 13 healthy individuals who were matched for age and sex (2:1 distribution) should be included in our study. ). Considering the possibility of dropouts, we planned to include 30 patients with pediatric-onset MS and 16 healthy controls, making a total of 46 participants, with an additional 20% added to each group.