Comparison of an Intermittent Vs. Continuous Walking Program in Persons with Multiple Sclerosis Using the 6 Minute Walk Test: A Randomized Crossover Pilot Study

Background: Difficulty with gait is one of the most common complaints of persons with MS (pwMS) and can be due to many causes, including neurogenic fatigue. Neurogenic fatigue is one of the most common MS symptoms, and can prevent pwMS from walking longer distances, thus limiting their ability to improve gait endurance. Intermittent walking, a technique where persons take breaks during walking rather than walking continuously may allow for pwMS to walk longer distances due to less accrual of fatigue, and as a result allow for improvement of gait endurance.

Objectives: The purpose of this pilot study was to examine whether a program of intermittent walking will result in a greater improvement in gait endurance in pwMS than a continuous walking program.

Methods:  A randomized crossover design was used. Subjects were randomized into intermittent (INT) and continuous (CONT) groups. All subjects performed a baseline 6-minute walk test (6MWT) following which they performed a training regime of eight 6-minute walks over a 4-week period, followed by a 6MWT posttest. Subjects in the INT group trained with three 2-minute walks interspersed with 2 minute seated rests, while the CONT group trained 6 minutes continuously.without taking any rests.  Subjects then underwent a 4-week detraining period, followed by another 4 week walking period where they performed whatever type of training they did not perform originally, with 6MWT’s again performed before and after the 8 training bouts. To determine whether the subjects found one type of training more fatiguing than the other, Visual Analog Fatigue Scale (VAFS) to measure subjective perception of fatigue for both walking conditions.

Results: 9 subjects  (6 female, 3 male, EDSS 3.9) completed both training conditions.  Intermittent training resulted in a significant (F (1,8) = 9.634, p< .015.  ) improvement in 6MWT (x̅=143.01’ ± 183.7) relative to continuous training, which resulted in a mean decrease of 59.2’. ±134.9. Subjective perceptions of fatigue while walking were not significantly different for the 2 walking conditions.

Conclusions: Despite the small sample size, intermittent gait training was clearly superior to continuous gait training in improving 6MWT performance. This suggests that gait endurance in MS may be better improved with gait training that emphasizes intermittent rests as opposed to walking continuously.