Objective: Ultrasound imaging is a widely used method for viewing musculoskeletal tissues. However, capturing movies of lumbar multifidus (LM) muscle with ultrasound imaging (video method) is a relatively new method, and its reliability has not been fully tested. The objective of this study was to compare the intra-rater reliability of two methods of ultrasound imaging of LM muscle, the traditional method (static images) and the video method, in healthy subjects conducted by a novice rater.
Methods: Images of LM thickness in 15 healthy subjects were captured and measured by static images and video methods. Intra-class correlation coefficient (ICC) with 95% confidence interval, standard error of measurement, and minimal detectable change were calculated to determine the reliability and precision of the LM thickness measurements.
Results: Excellent intra-rater reliability was demonstrated in measuring LM muscle thickness using both methods, with the intra-rater ICC ranging from 0.75 to 0.95.
Conclusion: The reliability of the LM thickness measurements in video ultrasound is similar to that in the static images method in healthy subjects.