Cuesta-Vargas AI, et al.
Arch Phys Med Rehabil. 2014 Jun;95(6):1093-9. doi: 10.1016/j.apmr.2014.01.023. Epub 2014 Feb 14.
Abstract
OBJECTIVE: To analyze the ability to discriminate between healthy individuals and individuals with chronic nonspecific low back pain (CNLBP) by measuring the relation between patient-reported outcomes and objective clinical outcome measures of the erector spinae (ES) muscles using an ultrasound during maximal isometric lumbar extension.
DESIGN: Cross-sectional study with screening and diagnostic tests with no blinded comparison.
SETTING: University laboratory.
PARTICIPANTS: Healthy individuals (n=33) and individuals with CNLBP (n=33).
INTERVENTIONS: Each subject performed an isometric lumbar extension. With the variables measured, a discriminate analysis was performed using a value ≥ 6 in the Roland and Morris disability questionnaire (RMDQ) as the grouping variable. Then, a logistic regression with the functional and architectural variables was performed. A new index was obtained from each subject value input in the discriminate multivariate analysis.
MAIN OUTCOME MEASURES: Morphologic muscle variables of the ES muscle were measured through ultrasound images. The reliability of the measures was calculated through intraclass correlation coefficients (ICCs). The relation between patient-reported outcomes and objective clinical outcome measures was analyzed using a discriminate function from standardized values of the variables and an analysis of the reliability of the ultrasound measurement.
RESULTS: The reliability tests show an ICC value >.95 for morphologic and functional variables. The independent variables included in the analysis explained 42% (P=.003) of the dependent variable variance.
CONCLUSIONS: The relation between objective variables (electromyography, thickness, pennation angle) and a subjective variable (RMDQ ≥ 6) and the capacity of this relation to identify CNLBP within a group of healthy subjects is moderate. These results should be considered by clinicians when treating this type of patient in clinical practice.
Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.