The 3-m backward walk test (3MBWT) is used to evaluate neuromuscular control, proprioception, protective reflexes, fall risk and balance. The aim of our study was to reveal the test-retest reliability and validity of the 3MBWT in Multiple Sclerosis patients.

Our study will be done as a "test-retest" design and psychometric properties of 3 m backward walking test in MS patients will be examined. Mini Mental State Examination, 3 m walk back test, Berg Balance Scale, Timed Up and Go, Timed 25 Step Walking Test and 4-Square Step Test will be applied to the patients. All evaluations will be made by the same physiotherapist. The second and third evaluation (retest) will be performed by the same physiotherapist two days after the first evaluation (test) and 2 weeks later to measure test-retest reliability. It will be preferable to collect data with the same evaluator to avoid inter-rater error rate between evaluations. It will be preferable to collect data with the same evaluator to avoid inter-rater error rate between evaluations.

The sample size, according to Lexell and Downham (2005), 40-50 participants should be included in reliability studies. Considering this recommendation, which defines the reliability of 3MBWT, it is planned to include 50 individuals with MS in our study.

The methodological model of the study is the validity and reliability study. Individuals who applied to Fırat University Training and Research Hospital after ethical approval and diagnosed with MS by a neurologist will be included in our study. It is planned to collect data from individuals who meet the inclusion criteria on a voluntary basis with the Helsinki Declaration. As demographic characteristics; Patients' age, gender, body weight, height, EDSS score, occupation and education status, as a history of the disease, the number of falls in the last year and the type of MS will be recorded. Inclusion criteria for the volunteers; Individuals with relapsing-remitting MS, with an EDSS score between 05≤ and ≤5.5, with an EDSS score between 18-65, and individuals with a score of 24 and above in the Mini Mental State Examination and who can independently walk a minimum of 10 m will be included. Also exclusion criteria for volunteers; High level spasticity of the lower limbs (Ashworth score 3 or 4), who had an acute MS attack or had a history of an attack within the last 1 month, had orthopedic or systemic problems that prevented participation in tests, had another known neuromuscular disorder other than MS, had visual involvement or diplopia, and Having a cardio-pulmonary problem that will prevent him from participating in tests.

Our study will be done as a "test-retest" design and psychometric properties of 3 m backward walking test in MS patients will be examined. Mini Mental State Examination, 3 m walk back test, Berg Balance Scale, Timed Up and Go, Timed 25 Step Walking Test and 4-Square Step Test will be applied to the patients. All evaluations will be made by the same physiotherapist. The second and third evaluation (retest) will be performed by the same physiotherapist two days after the first evaluation (test) and 2 weeks later to measure test-retest reliability. It will be preferable to collect data with the same evaluator to avoid inter-rater error rate between evaluations.

The sample size, according to Lexell and Downham, 30-50 participants should be included in reliability studies . Considering this recommendation, which defines the reliability of 3MBWT, it is planned to include 50 individuals with MS in our study.

Statistical analysis SPSS for Windows 20.00 computer package program will be used for all statistical analyzes. Descriptive statistical information will be given as mean ± standard deviation (x ± SD) or%. Interclass Correlation Coefficients (ICC) and Cronbach's coefficients values will be examined for the reliability and internal consistency of 3MGDYT. The data will be analyzed with appropriate statistical methods and the statistical significance level will be accepted as p <0.05.

Inclusion Criteria:

• Individuals with relapsing-remitting MS, with an EDSS score between 05≤ and ≤5.5, with an EDSS score between 18-65, and individuals with a score of 24 and above in the Mini Mental State Examination and who can independently walk a minimum of 10 m will be included.

Exclusion Criteria:

• Exclusion criteria for volunteers; High level spasticity of the lower limbs (Ashworth score 3 or 4), who had an acute MS attack or had a history of an attack within the last 1 month, had orthopedic or systemic problems that prevented participation in tests, had another known neuromuscular disorder other than MS, had visual involvement or diplopia, and Having a cardio-pulmonary problem that will prevent him from participating in tests.

Individuals who applied to Fırat University Training and Research Hospital and diagnosed with MS by a neurologist will be included.