The Functional Gait Assessment in People with Multiple Sclerosis: Validity and Sensitivity to Change

Background: Assessments of balance and walking are often performed in rehabilitation of people with multiple sclerosis (MS). The Functional Gait Assessment (FGA) is a test of walking balance including challenging items such as walking with a narrow base of support, with eyes closed, and backward. The aim was to investigate the validity (concurrent, discriminant, and known-groups) and sensitivity to change of the modified FGA in ambulatory individuals with MS.

Methods: A convenience sample of 87 individuals with MS was included (mean age, 54 years; 79% women). Concurrent and discriminant validity was investigated using tests of dynamic balance and the Multiple Sclerosis Walking Scale and Multiple Sclerosis Impact Scale (MSIS). Known-groups validity was investigated with self-reported number of falls and use of walking devices. Sensitivity to change was investigated with data from a group balance training study.

Results: The median FGA score was 15 (range, 1-26). Concurrent validity with tests of dynamic balance was moderate to strong, with the Timed Up and Go test having the highest correlation coefficient (rho = -0.74). Discriminant validity was shown with a low correlation coefficient with the MSIS psychological subscale (rho = 0.14). The FGA scores differed significantly for users of walking devices versus nonusers but not for reported falls. Sensitivity to change was moderate to low.

Conclusions: The FGA is a valid measure of balance during walking in people with MS, but further investigation is required for the ability to detect people at risk for falls.