Oxygen cost of walking in persons with Multiple Sclerosis
The impairment of walking is a hallmark feature of neurological diseases such as multiple sclerosis (MS). The oxygen cost (O2 cost, ml/kg/m) of walking is elevated in persons with MS, particularly as a function of increasing disability status.
The current study examined symptomatic (i.e., fatigue (Fatigue Severity Scale), pain (SF-MPQ), anxiety, and depression (HADS)) and gait variables (i.e., velocity (cm/sec), cadence (steps/min), and step length (cm)) that might explain why disability status is associated with O2 cost of walking in persons with MS. 82 ambulating MS patients with a broad range of disability (self reported by PDDS-scale) were included.
Indeed, patients with worse disability demonstrated worse walking efficiency and fatigue. The main explanation for this association is cadence (steps/min); it is discussed that slower cadence is associated with increases in mediolateral displacement of the center of mass (i.e., poor biomechanical efficiency) during walking in healthy adults and in persons with Down syndrome, presumably resulting in energetic penalties during walking (fatigue, higher O2 cost). This creates possibilities for intervention: improved cadence might be accomplished through rhythmic auditory stimulation (RAS), as one pilot study reported large improvements in cadence following a one-week RAS intervention. > From: Sandroff et al., Mult Scler Int 2014 (2014) 162765. All rights reserved to Brian M. Sandroff et al.. Click here for the Pubmed summary.