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

Tomoya Ishigaki; Hiroki Kubo; Keishi Yoshida; Natsuki Shimizu; Tatsuya Ogawa

doi:10.3389/fresc.2024.1384369

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

Front Rehabil Sci. 2024 Apr 16:5:1384369. doi: 10.3389/fresc.2024.1384369. eCollection 2024.

Authors

Tomoya Ishigaki¹, Hiroki Kubo², Keishi Yoshida³, Natsuki Shimizu⁴, Tatsuya Ogawa⁵

Affiliations

¹ Department of Physical Therapy, Faculty of Rehabilitation Sciences, Nagoya Gakuin University, Aichi, Japan.
² Department of Physical Therapy, Faculty of Nursing and Rehabilitation, Konan Women's University, Hyogo, Japan.
³ Department of Rehabilitation, Senri-Chuo Hospital, Osaka, Japan.
⁴ Department of Physical Therapy, Faculty of Health and Medical Care, Saitama Medical University, Saitama, Japan.
⁵ Department of Rehabilitation, Nishiyamato Rehabilitation Hospital, Nara, Japan.

Abstract

Introduction: We investigated the reliability and validity of the 2-min step test (2MST) for assessing the exercise endurance of individuals with stroke and lower-limb musculoskeletal disorders.

Participants and methods: The participants were 39 individuals with stroke and 42 with lower-limb musculoskeletal disorders (mainly hip fractures) from the convalescent rehabilitation wards of four hospitals. The concurrent validity and congruence between the 2MST and the 6-min walk test (6MWT) and construct validity by hypotheses testing, including mobility and lower limb muscle strength, were also confirmed. A subset of participants (stroke-group, n = 15; musculoskeletal-group, n = 19) underwent a retest 2MST for our evaluation of relative and absolute reliability using the intraclass correlation coefficient (ICC_1,1) and Bland-Altman plot.

Results: Both groups showed a moderate correlation between the 2MST and 6MWT (ρ = 0.55-0.60), but the congruence was not sufficient. The 6MWT was correlated with mobility in both groups and with muscle strength in the stroke group, whereas the 2MST did not show a significant correlation with mobility. The relative reliability was excellent in both groups (ICC_1,1 > 0.9). In terms of absolute reliability, the width of the limit of agreement was 18.8% for the stroke group and 15.4% for the musculoskeletal group, relative to their respective sample means of 2MST. A fixed bias was identified in the stroke group, in which step counts increased by 6.5 steps upon retesting.

Discussion: Our analyses revealed that the 2MST is a valid and reliable tool for assessing the exercise endurance of individuals with stroke or lower-limb musculoskeletal disorders. However, it is necessary to validate the absolute reliability observed herein by using a larger sample size. In addition, when assessing the exercise endurance of individuals with stroke, it may be necessary to consider the potential bias of an increased step count during retesting.

Keywords: exercise capacity; exercise endurance; lower-limb musculoskeletal disorder; stroke; two-minute step test.

Grants and funding

The authors declare financial support was received for the research, authorship, and/or publication of this article.