Validity and reliability of the 2-min step test in individuals with stroke and lower-limb musculoskeletal disorders.

The study did not compare the 2-minute step test with maximal or peak oxygen uptake, so it did not directly measure exercise capacity. The heart-rate reserve during both tests was only between 15% and 20%, indicating a low exercise load. The reliability sample was small (15 stroke and 19 lower-limb musculoskeletal disorders), and the 95% confidence intervals for the limits of agreement were wide. Participants were not blinded to their test results, and the treating physiotherapists collected data, which could introduce examiner bias. All participants held a handrail during the step test, so the results may not apply to the test performed without support. People who could not elevate the limb to the required height were excluded, and only participants able to walk with supervision using an aid or orthosis were included. Individuals who had undergone total hip arthroplasty did not participate, so the findings do not cover that group. No sensitivity analysis was performed, so the stability of results across subgroups is unknown.

The authors declare financial support was received for the research, authorship, and/or publication of this article. The study was supported by the Nagoya Gakuin University Research Grant for fiscal years 2021-2022.

Do not treat the 2-minute step test as interchangeable with the 6-minute walk test. Although the scores were moderately related, the 95% prediction interval for 6-minute walk distance from the step test was very wide (177.1 to 462.9 metres in stroke and 128.1 to 499.9 metres in lower-limb musculoskeletal disorders). In stroke, a retest increase of approximately 6.5 steps may be a fixed bias rather than true improvement.