The functional reach test in people with multiple sclerosis: a reliability and validity study.

Area of Science:

• Neurology
• Rehabilitation Science
• Biomedical Engineering

Background:

• Limits of stability (LOS) is crucial for balance in multiple sclerosis (MS).
• The functional reach test (FRT) is a clinical LOS assessment tool.
• Psychometric properties of the FRT in MS are not well-established.

Purpose of the Study:

• Assess intrarater, interrater, and test-retest reliability of the FRT in MS patients.
• Determine the minimum detectable change (MDC) for FRT measurements.
• Evaluate concurrent and discriminant validity of the FRT.
• Identify a cutoff distance to differentiate MS patients from healthy individuals and fallers from non-fallers within the MS group.

Main Methods:

• 43 MS patients and 36 healthy controls participated.
• FRT was administered alongside other balance and disability measures.
• Reliability was assessed through repeated measures by the same rater, different raters, and at different time points.
• Validity was examined by correlating FRT with other measures and comparing group differences.

Main Results:

• FRT demonstrated good to excellent reliability (ICC 0.80-0.97).
• Minimum detectable change (MDC) was 8.28 cm.
• FRT showed significant correlation with other outcome measures (r=0.31-0.79).
• A cutoff of 35.5 cm distinguished MS patients from healthy individuals; 28.5 cm did not differentiate fallers from non-fallers in MS.

Conclusions:

• The FRT is a reliable and valid tool for assessing LOS in people with MS.
• Its ease of administration makes it practical for clinical use.
• FRT can effectively differentiate individuals with MS from healthy controls.