Cognitive motor interference during walking in multiple sclerosis using an alternate-letter alphabet task

Yvonne C. Learmonth, Brian M. Sandroff, Lara Pilutti, Rachel E. Klaren, Ipek Ensari, Barry J. Riskin, Roee Holtzer, Robert W Motl

Research output: Contribution to journalArticlepeer-review


Objective To examine cognitive motor interference (CMI) during walking using a simple, standardized, and well-refined alphabet dual-task (DT) paradigm in individuals with multiple sclerosis (MS) in whom cognitive and walking impairment often co-occur. Design A single time point, cross-sectional study. Setting A university clinical laboratory. Participants Individuals with MS (N=61; mean age ± SD, 50.8±9.3y) performed 4 walking trials over a 4.6-m walkway to determine gait parameters. Interventions Not applicable. Main Outcome Measures Gait parameters were assessed over 4 walking trials. The first 2 walks involved the single task (ST) of walking only; the second 2 walks involved participants performing the DT of reciting alternate letters of the alphabet while walking. The gait parameters recorded during the ST and DT walks were used to compute a dual-task cost (DTC) of walking (% change in gait parameter between ST and DT walks) as a metric of CMI. Results Our multivariate analysis with univariate follow-ups indicated CMI during walking based on slower velocity (ηp 2=.59; F=84.6; P<.001) and cadence (ηp 2=.46; F=51.6; P<.001), shorter step length (ηp 2=.38; F=36; P<.001), and increased step time (ηp 2=.34; F=31; P<.001) and double-support time (ηp 2=.31; F=27.3; P<.001) in DT versus ST conditions. The DTC of walking for the gait parameters was not correlated with clinical (disability, disease duration) and demographic (eg, education, age) factors (all |r|≤.240). Conclusions The alphabet DT paradigm is easily administered and well refined. We highlight its ability and acceptability to determine CMI during walking in people with MS, independent of disease status.

Original languageEnglish (US)
Pages (from-to)1498-1503
Number of pages6
JournalArchives of Physical Medicine and Rehabilitation
Issue number8
StatePublished - Aug 2014


  • Cognition
  • Multiple sclerosis
  • Rehabilitation

ASJC Scopus subject areas

  • Physical Therapy, Sports Therapy and Rehabilitation
  • Rehabilitation


Dive into the research topics of 'Cognitive motor interference during walking in multiple sclerosis using an alternate-letter alphabet task'. Together they form a unique fingerprint.

Cite this