Ultrasound Imaging Analysis of the Lumbar Multifidus Muscle Echo Intensity: Intra-Rater and Inter-Rater Reliability of a Novice and an Experienced Rater

Abstract

Background and Objectives: Ultrasound echo intensity (EI) of the lumbar multifidus muscle (LMM) could offer valuable insights regarding muscle quality in people with low back pain (LBP). However, whether the rater’s experience noticeably influences the reliability and precision of LMM EI measurements has not been established. The aims of this study were to investigate the intra-rater and inter-rater reliability of LMM EI measurements, and to compare the reliability and SEM between a novice and an experienced rater. Materials and Methods: Twenty athletes (10 females, 10 males) with a history of LBP were included in this study. Transverse ultrasound images of LMM were taken at L5 in prone. LMM EI measurements were obtained bilaterally by tracing the maximum ROI representing the LMM cross-sectional area (CSA), avoiding the inclusion of bone or surrounding fascia. All measurements were performed by two novice raters and an experienced researcher. Each measurement was acquired by each rater three times for each side on three different images, and the average was used in the analyses. Raters were blinded to each other’s measurements and the participant’s clinical information. Intra-class correlation coefficients (ICCs) were obtained to assess the intra-rater and inter-rater reliability. Results: The intra-rater ICC values for the LMM measurements for the experienced rater were excellent (ICC all > 0.997). The inter-rater reliability ICC values showed moderate to excellent reliability (0.614 to 0.994) and agreement between the novice raters and the experienced rater, except for Novice 1 for the right LMM, which revealed lower ICCs and a wider 95% CI. Intra-rater and inter-rater reliability results were similar when separately looking at the right and left side of the muscle and participant gender. Conclusions: Our findings support the clinical use of ultrasound imaging for the assessment of LMM EI in individuals with LBP.

Correlation between Body Composition and Inter-Examiner Errors for Assessing Lumbar Multifidus Muscle Size, Shape and Quality Metrics with Ultrasound Imaging

“…All US measurements were performed by two examiners, one experienced (+10 years of experience in the use of musculoskeletal assessments) and one novice (less than one year of experience using US). The rationale for assessing only inter-examiner reliability between a novel and an experienced examiner was based on the worse reliability estimates reported in the literature (involving greater errors) compared with other conditions (intra-examiner reliability or inter-examiner reliability between two experienced examiners) [37][38][39].…”

“…As conducted in previous studies [27,37], the experienced examiner trained the novice on the procedures (patients' positioning, transducer placement, US settings. .…”

“…Immediately after conducting the body composition analyses, participants were placed in the prone position minimizing their lumbar lordosis by using a pillow under their abdomen and asked to relax their paraspinal musculature during the procedure for minimizing muscle changes due to muscle contraction [37].…”

Effects of Virtual Reality Exercises versus Isokinetic Exercises in comparison with Conventional Exercises on the Imaging Findings and Inflammatory Biomarker Changes in Soccer Players with Non-Specific Low Back Pain: A Randomized Controlled Trial

“…The participants were placed in the prone position and a pillow was kept under the abdomen to straighten the curve. The measurements were taken from the apex of the facet joint of L4, and on the junction between the thoracolumbar fascia and subcutaneous fat, and have good intra-rater and inter-rater reliability [27].…”

Investigation of the Relationship Between Multifidus Muscle and Lumbar Disc Herniation Through Magnetic Resonance Imaging

“…[24] The most preferred imaging techniques for evaluation of the lumbar MM are MRI, as well as computed tomography (CT) and ultrasound. [1,21,25] The main purpose of our study is to determine whether there is a relationship between lumbar disc degeneration and the degree of fatty infiltration as well as the diameter of the LMM. The second aim was to investigate the degree of LMM fatty infiltration regarding the age and gender of patients.…”