Accelerometry and Its Association With Objective Markers of Walking Limitations in Ambulatory Adults With Multiple Sclerosis

Motl RW, Dlugonski D, Suh Y, Weikert M, Fernhall B, Goldman M. Accelerometry and its association with objective markers of walking limitations in ambulatory adults with multiple sclerosis. Arch Phys Med Rehabil 2010; 91:1942-7. Objective: To validate accelerometry based on its correlations with 6-minute walk distance (6MWD) and oxygen cost of walking as objective markers of walking limitations in multiple sclerosis (MS). Design: Cross-sectional. Setting: Laboratory and general community. Participants: Ambulatory participants with MS (N=26) who resided in the local community. Interventions: Not applicable. Main Outcome Measures: Patient Determined Disease Steps (PDDS) scale and Multiple Sclerosis Walking Scale-12 (MSWS-12); 6-minute walk test while wearing a portable metabolic unit for measuring the 6MWD and oxygen cost of walking; accelerometer during the waking hours of a 7-day period. Results: The average of total daily movement counts from the accelerometer correlated significantly and strongly with MSWS-12 scores (rho=-.681, P=.001), PDDS scores (rho=-.609, P=.001), 6MWD (rho=.519, P=.003), and oxygen cost of walking (rho=-.541, P=.002). Conclusions: We provide evidence that further supports the validity of accelerometry as a measure of walking limitations in ambulatory persons with MS.