Multiple sclerosis (MS) is a chronic disease of the central nervous system associated with a wide range of motor and non-motor symptoms. Sleep disturbances, fatigue, altered interoceptive perception, and impairments in upper and lower extremity functional capacity are commonly observed in individuals with MS. Decreased sleep quality may exacerbate fatigue and negatively affect daily activities and independence. Therefore, examining the relationships between sleep quality, interoception, fatigue, and extremity functional capacity is essential for effective disease management and the preservation of quality of life in individuals with MS.

The aim of this study is to compare interoception, fatigue, and upper and lower extremity functional capacity between individuals with MS who have good and poor sleep quality and to evaluate the relationships among these variables. By comparing MS patients based on sleep quality, this study seeks to clarify the impact of sleep quality on interoceptive processes, fatigue levels, and functional capacity.

Inclusion Criteria:

• Diagnosed with multiple sclerosis by a specialist physician
• Aged between 18 and 65 years
• No MS relapse within the last 3 months
• Expanded Disability Status Scale (EDSS) score between 1.0 and 5.0
• Ability to stand independently for at least 60 seconds without the use of any assistive device
• No additional neurological disorder or circulatory/visual impairment that may affect balance
• Cognitive function score >24 on the Mini-Mental State Examination (MMSE)
• Provided written informed consent after receiving detailed information about the study

Exclusion Criteria:

• Use of corticosteroids within the last 4 weeks
• Pregnancy
• Presence of spinal deformities, disc herniation, or other spinal pathologies
• Presence of orthopedic conditions affecting the hip, knee, or ankle
• History of surgery involving the spine, hip, knee, or ankle
• Change in medication within the last month

The study population consists of individuals diagnosed with multiple sclerosis (MS) by a specialist physician. Eligible participants are adults aged 18-65 years, with an Expanded Disability Status Scale (EDSS) score between 1.0 and 5.0, who have not experienced an MS relapse within the past three months. Participants must be able to stand independently for at least 60 seconds without assistive devices and have sufficient cognitive function, defined as a Mini-Mental State Examination score greater than 24. Exclusion criteria include other neurological, visual, or circulatory conditions affecting balance, recent corticosteroid use, pregnancy, significant orthopedic or spinal disorders, and recent medication changes. Written informed consent is obtained from all participants prior to enrollment.