The six-minute walk test for children with cerebral palsy

Abstract

The 6-min walk test (6MWT) is increasingly being used as a measure of 'functional ability' in young people with cerebral palsy, despite a lack of published evidence that it is reliable for this population. This study aimed to determine the test-retest reliability of the 6MWT for ambulant 11-17-year-old adolescents with cerebral palsy. Adolescents with cerebral palsy were invited to participate in a single testing session. They performed the 6MWT twice under controlled conditions (standardized 10 m course layout, standardized instructions and encouragement), with a 30-min rest. Forty-one participants (response rate 36.6%) were recruited (26 males, 15 females; mean age 13.6+/-1.6 years). No significant difference was found between the 6-min walk distance in trials 1 and 2 for the whole group (448.7+/-96.9 m vs. 449.5+/-102.1 m; P=0.81) or by sex and gross motor function subsets. The test-retest intraclass correlation coefficient was 0.98. Bland-Altman analyses revealed a bias of only -0.9 m, and that in 95% of cases, the second 6-min walk distance would fall within +/-43.1 m of the first 6-min walk distance. All participants successfully managed the testing procedure, appeared to understand what was expected of them, and experienced no ill effects from the 6MWT. These results indicate that, when carried out according to American Thoracic Society guidelines, the 6MWT is a reliable test for young ambulant people with cerebral palsy.

Test–retest reliability of a 1-min walk test in children with bilateral spastic cerebral palsy (BSCP)

“…Their results also indicated that children who were able to walk longer distances at baseline were more likely to increase their walking distance on retest, thus warranting further investigation of a practice walk in children with a GMFCS level I. A further study by Maher et al [9], which also did not include a practice walk (carried out in children with CP), found a repeatability of 43.1 m with minimal systematic bias (0.85 m) between WTs conducted on the same day. Thus, they also concluded that a practice walk was not necessary before testing.…”

“…Previous papers on the latter [7][8][9] have documented ICC scores of 0.99, 0.98 and 0.98 Table 1 Means AE S.D. (range) for subject characteristics and study data.…”

“…Despite the growing use of WTs as a useful outcome tool within areas of rehabilitation medicine [3][4][5][6], research regards their validity and reliability in children and adults with disability is just starting to appear within the literature. Three recent papers concluded high test-retest reliability of the 6-min protocol in adults [7] and children [8,9] with cerebral palsy (CP), although results conflicted with regards to the necessity of a practice walk. Considerably less work has been conducted on WTs of lesser duration.…”

Identification of a core set of exercise tests for children and adolescents with cerebral palsy: a Delphi survey of researchers and clinicians

“…15,16 Reliability was found for the 6-MWT (ICC=0.93, 0.91, and 0.99 for GMFCS levels I, II, and III respectively). 17,18 For maximal exercise tests, the 10-meter shuttle run tests (SRT-I; for children classified at GMFCS level I [starting speed 5km per h] and SRT-II for children classified at GMFCS level II [starting speed 2km per h]; ICC>0.97) 19 and the McMaster all-out cycle test (r s >0.72-0.92) 4 were the only two tests with published (test-retest) reliability data in CP. One participant provided additional unpublished psychometric data regarding a maximal exercise test (7.5m shuttle walk ⁄ run test) for children classified at GMFCS level III.…”

“…The outcome measures were listed within each 40 Walking + + ) 5-MWT a, 41,42 Walking + + ) 6-MWT 17,18 Walking + + ) 8-MWT 43 Walking + + ) 600yd walk ⁄ run test 44 Walking + + ) 30-s walk test 44 Walking + + ) Half-mile walk ⁄ run test 45 Walking + ) ) Arm-cranking ergometer protocol 24 Arm cranking + + ) 5-min treadmill economy test 46 Walking + ) ) EEI-HR overground walk test 13 Walking + ) ) 6-min wheelchair riding test a Riding ) + + Maximal Bruce protocol 47 Walking + ) ) 10m SRT (SRT-I and SRT-II) 19 Walking + ) ) Treadmill test 19 Walking + ) ) Treadmill test 48 Walking + ) ) Treadmill test 38 Walking + ) ) McMaster all-out protocol cycle test 4 Cycling ⁄ arm cranking + + + Ergometer test (cycle or cranking) 49 Cycling of the GMFCS levels (levels I and II were combined because the responses were the same for the two levels). The submaximal exercise test for which reliability and concurrent validity data were found in CP was the 1-minute walk test (MWT; intraclass correlation [ICC]=0.94 for GMFCS levels I, II, III, and IV; significant correlation between Gross Motor Function Measure score and the distance covered during the 1min walk).…”