Physical fitness, walking performance, and gait in multiple sclerosis

Background Walking impairment is a prevalent, life-altering feature of multiple sclerosis (MS). There has been recent speculation that physiological deconditioning (i.e., reductions in aerobic capacity, balance, and muscular strength) contributes to walking and gait impairments in MS. Objective This study examined the associations among aerobic capacity, balance, and lower-limb strength asymmetries, walking performance, and gait kinematics in 31 persons with MS and 31 matched controls. Methods Participants underwent standard assessments of peak aerobic capacity, muscular strength (i.e., asymmetry between knee muscles), and balance. Walking performance was measured using the timed 25-ft walk (T25FW) and six-minute walk (6MW). Gait parameters were captured using a GaitRite™ electronic walkway. Results Aerobic capacity, balance, and knee-extensor asymmetry were associated with walking performance and gait in persons with MS (r =.2-.6) and explained differences in walking and gait variables between MS and control groups (δR² =.27-.34). Aerobic capacity and lower-limb strength asymmetries, but not balance, explained significant variance in walking performance and gait kinematics in the MS sample (R² =.32-.58). Conclusions Physiological deconditioning explains variability in walking disability in persons with MS and might represent a target of multimodal exercise training interventions for improving mobility outcomes in this population.