Reliability, validity, and norms of the 2-min walk test in children with and without neuromuscular disorders aged 6–12

Abstract

Purpose: The 2-min walk test may be more appropriate functional exercise test for young children. This study aimed to examine the 2-min walk test’s reliability; validity; and minimal clinically important difference; and to establish norms for children aged 6–12.

Methods: Sixty-one healthy children were recruited to examine the 2-min walk test’s reliability. Forty-six children with neuromuscular disorders (63% cerebral palsy) were recruited to test the validity. The normative study involved 716 healthy children without neuromuscular disorders (male = 51%, female = 49%). They walked at a self-selected speed for 2 min along a smooth, flat path 15 m in length.

Results: The mean distance covered in the 2-min walk test was 152.8 m (SD =27.5). No significant difference was found in the children’s test-retest results (p > 0.05). The intra- and inter-rater reliability were high (all intra-class correlation coefficients >0.8). All children, except one with neuromuscular disorders, completed the 2-min walk test, of which the minimal clinically important difference at 95% confidence interval was 23.2 m for the entire group, 15.7 m for children walking with aids, and 16.6 m for those walking independently.

Conclusions: The 2-min walk test is a feasible, reliable, and valid exercise test for children with and without neuromuscular disorders aged 6–12. The first normative references and minimal clinically important difference for children with neuromuscular disorders were established for children of this age group.

Implications for rehabilitation

• The 2-min walk test is a feasible, safe, reliable, and valid time-based walk test for children aged 6–12 years.

• Normative references have been established for healthy children aged 6–12 years.

• Minimal clinically important difference at 95% confidence interval were calculated for children with neuromuscular disorders who walked without aids (i.e., independent and stand-by supervision) and those who walked with aids equal to 16.6 and 15.7 m, respectively.

• Distance covered by the healthy children in the 2 min did not correlate with age, gender, height, and weight of the children.

Keywords:

• Exercise test
• psychometrics
• outcome assessment (healthcare)
• child
• walking
• reproducibility of results

Acknowledgements

The authors would like to thank the following organizations for help in the recruitment of participants:

AD & FD of Pok Oi Hospital Mrs Cheng Yam On Millennium School

Hong Kong Christian Service Pui Oi School

Hong Kong Red Cross John F Kennedy Centre

Hong Kong Red Cross Princess Alexandra School

HKSA Jockey Club Elaine Field School

Kwun Tong Government Primary School (Sau Ming Road)

Tsung Tsim Mission of Hong Kong Kau Yan Church Kau Yan Service Centre

The authors would also like to thank Mr. Keith Cheung for his assistance in the collection and management of data, and all the students (and their parents) who participated in this study.

This study was approved by the ethics committee of The Hong Kong Polytechnic University (HSEARS20150310001). Informed written consent was obtained from the parents of the children before the test began.

Disclosure statement

The authors declare that they have no competing interests.

Additional information

Funding

The project was fully funded by the Hong Kong Research Grants Council Early Career Scheme 2014/15 (Project no. 25101014), granted to the first author. The second author was employed using this funding. The funding body had no role in the design of the study; the collection, analysis, and interpretation of data; or in the writing of the manuscript.