Reliability and Construct Validity of the Six-Minute Step Test in Individuals With Non-Specific Chronic Low Back Pain
Francisco Basílio da Silva-Júnior1, André Pontes-Silva1, Yane Pelicer-Marques2
1Federal University of Maranhão, São Luís, Maranhão, Brazil.
Summary
The six-minute step test (6MST) shows excellent reliability and validity for assessing individuals with non-specific chronic low back pain (NSCLBP). This practical test can effectively measure stepping performance in this patient group.
Area of Science:
- Rehabilitation Medicine
- Clinical Assessment
- Pain Management
Background:
- Non-specific chronic low back pain (NSCLBP) affects stepping performance.
- Evidence on the six-minute step test (6MST) measurement properties in NSCLBP is limited.
Purpose of the Study:
- Evaluate the inter-rater reliability of the 6MST in individuals with NSCLBP.
- Assess the construct validity of the 6MST using a known-groups approach.
Main Methods:
- Cross-sectional psychometric study comparing 31 individuals with NSCLBP and 31 healthy controls.
- Two blinded raters administered the 6MST independently 7 days apart.
- Inter-rater reliability assessed using ICC, SEM, MDC, and Bland-Altman analysis; construct validity examined by comparing group performance.
Main Results:
- Excellent inter-rater reliability for 6MST (ICC=0.915 in NSCLBP group).
- Satisfactory construct validity demonstrated by significantly lower performance in the NSCLBP group (mean difference 33-37 steps, Cohen's d=1.76-1.91).
- NSCLBP group showed lower target heart rate attainment and greater post-test pain increase.
Conclusions:
- The 6MST is a reliable and valid measure for stepping performance in individuals with NSCLBP.
- The test is practical and cost-effective for clinical use in this population.
- Observed heart rate responses do not indicate differences in exercise tolerance or cardiopulmonary function.
