title: Reliability of the walking energy cost test and the six-minute walk test in boys with Duchenne muscular dystrophy.
abstract: The walking energy cost test (WECT) is a useful tool when measuring ambulatory function in children with motor disorders. However, data on the reliability of this test in Duchenne muscular dystrophy (DMD) is not available. In this study we established the reliability of the WECT and the commonly used six-minute walk test (6MWT) in 19 boys with DMD, aged 6-12years. Participants performed the WECT and 6MWT twice within three weeks. Reliability was determined for walking distance (D, m) and gross energy cost (EC, Jkg(-1)m(-1)), using the intraclass correlation coefficient (ICC2,1) and smallest detectable change (SDC). Reliability for walking distance was good, with an ICC of 0.92 [95% CI: 0.81-0.97] and 0.83 [CI: 0.53-0.94] for the 6MWT and WECT, respectively, and an ICC of 0.85 [CI: 0.64-0.94] for gross EC. SDCs were 12.2% for D6MWT, 12.7% for DWECT and 18.5% for gross EC. In conclusion, in young boys with DMD, the reliability of both the WECT and 6MWT for assessing walking distance is adequate. Gross EC, as assessed with the WECT is also reliable and sufficiently sensitive to detect change in walking strain following interventions at group level.
authors.affiliation: Department of Rehabilitation Medicine and MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: J C E
authors.initials: JC
authors.lastname: Kempen
authors.affiliation: Department of Rehabilitation Medicine and MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Harlaar
authors.affiliation: Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: A J
authors.initials: AJ
authors.lastname: van der Kooi
authors.affiliation: Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: I J M
authors.initials: IJ
authors.lastname: de Groot
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: van den Bergen
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: E H
authors.initials: EH
authors.lastname: Niks
authors.affiliation: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: J J G M
authors.initials: JJ
authors.lastname: Verschuuren
authors.affiliation: Department of Rehabilitation Medicine and MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands; Department of Rehabilitation, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Electronic address: m.a.brehm@amc.uva.nl.
authors.forename: M A
authors.initials: MA
authors.lastname: Brehm
mesh_terms: D002648:Child; D004734:Energy Metabolism; D005080:Exercise Test; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000503:physiopathology* / Q000628:therapy; D016138:Walking / Q000502:physiology*
keywords: Duchenne muscular dystrophy; Energy cost of walking test; Reliability; Six minute walking test; Walking ability