Oxygen cost of treadmill and over-ground walking in mildly disabled persons with multiple sclerosis

Walking impairment is a ubiquitous feature of multiple sclerosis (MS) and the O₂ cost of walking might quantify this dysfunction in mild MS. This paper examined the difference in O₂ cost of walking between persons with MS who have mild disability and healthy controls and the correlation between the O₂ cost of walking and disability. Study 1 included 18 persons with mild MS and 18 controls and indicated that the O₂ cost of walking was significantly higher in MS than controls and that disability was significantly associated with the O₂ cost of slow, moderate, and fast treadmill walking. Study 2 included 24 persons with mild MS and indicated that disability was significantly correlated with O₂ cost of comfortable, fast, and slow over-ground walking. We provide evidence that the O₂ cost of walking is an indicator of walking dysfunction in mildly disabled persons with MS and should be considered in clinical research and practice.