Testing walking performance in patients with low back pain: will two minutes do instead of six minutes?

Abstract

Purpose

The six-minute walk test (6MWT) can assess walking function but is time-consuming. We investigate the correlation of performance over the first two minutes of the 6MWT (2MWT#) and the 6MWT. We also evaluate the 2MWT#’s ability to predict 6MWT results, assess correlations to secondary explanatory outcomes, and assess the ability to discriminate between clinical subgroups.

Material and methods

A cross-sectional study of 124 participants with LBP. Correlations between the 2MWT# and 6MWT and secondary outcomes were evaluated using the Pearson product-moment correlation coefficient. The predictive ability of the 2MWT# was defined as the residual distance between the observed 6MWT and three times the 2MWT#. Differences between clinical subgroups were evaluated using the Wilcoxon rank test.

Results

The 2MWT# and 6MWT correlated highly (r = 83, 95% CI 0.76 − 0.87). The 2MWT# overestimated 6MWT results with 46.8 meters (SD 67.0). Both tests correlated with secondary outcomes and discriminated similarly between clinical subgroups.

Conclusions:

The 2MWT# correlates highly with 6MWT but overestimates the observed 6MWT by 9%. Because it is shorter, possibly less burdensome, and with little or no loss of discriminatory ability, we consider it a legitimate alternative to the 6MWT in patients with LBP.

Implications for rehabilitation

• Walking function is often affected in patients with low back pain (LBP).

• The six-minute walk test (6MWT) is frequently used to assess walking function but is time-consuming.

• A shorter two-minute walk test is a legitimate alternative in patients with LBP as it correlates highly with the 6MWT and has little or no loss of discriminatory ability between clinical subgroups.

Keywords:

• Low back pain
• walk test
• disability evaluations
• functional capacity
• 6-minute walk test

Acknowledgements

The authors like to thank Dorte Lemvigh for assisting with data collection and OPEN - Open Patient data Exploratory Network, SDU, for data storage.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.