The 6-minute walk test as a new outcome measure in Duchenne muscular dystrophy.
Walking abnormalities are prominent in Duchenne muscular dystrophy (DMD). We modified the 6-minute walk test (6MWT) for use as an outcome measure in patients with DMD and evaluated its performance in 21 ambulatory boys with DMD and 34 healthy boys, ages 4 to 12 years. Boys with DMD were tested twice, approximately 1 week apart; controls were tested once. The groups had similar age, height, and weight. All tests were completed. Boys who fell recovered rapidly from falls without injury. Mean +/- SD [range] 6-minute walk distance (6MWD) was lower in boys with DMD than in controls (366 +/- 83 [125-481] m vs. 621 +/- 68 [479-754] m; P < 0.0001; unpaired t-test). Test-retest correlation for boys with DMD was high (r = 0.91). Stride length (R(2) = 0.89; P < 0.0001) was the major determinant of 6MWD for both boys with DMD and controls. A modified 6MWT is feasible and safe, documents disease-related limitations on ambulation, is reproducible, and offers a new outcome measure for DMD natural history and therapeutic trials.
McDonald
Craig M
CM
Department of Physical Medicine and Rehabilitation, University of California Davis School of Medicine, Sacramento, California, 95817, USA. cmmcdonald@ucdavis.edu
Henricson
Erik K
EK
Han
Jay J
JJ
Abresch
R Ted
RT
Nicorici
Alina
A
Elfring
Gary L
GL
Atkinson
Leone
L
Reha
Allen
A
Hirawat
Samit
S
Miller
Langdon L
LL
D002648:Child; D002675:Child, Preschool; D005080:Exercise Test / Q000379:methods* / Q000592:standards; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis* / Q000503:physiopathology*; D017063:Outcome Assessment, Health Care; D015203:Reproducibility of Results; D013997:Time Factors; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology*