Reliability of ultrasound imaging of the transversus abdominis muscle in asymptomatic subjects

[Purpose] The purpose of this study was to assess intra-rater and inter-rater procedural reliability of ultrasound imaging measurements of transversus abdominis thickness. [Subjects] Thirty therapists who attended the B Hospital in Hwaseong participated in the study. [Methods] Two examiners assessed transverse abdominis thickness at rest and during contraction. Intra-class correlation coefficient with 95% confidence interval and, standard error of measurement were calculated. [Results] The intra-rater procedural reliability of ultrasound imaging measurements of transverse abdominis thickness, assessed using the intra-class correlation coefficient, was 0.65–0.86 (within-day, 0.65–0.86; between-day, 0.77–0.85). The inter-rater procedural reliability of ultrasound imaging measurements of transverse abdominis thickness, assessed using the intra-class correlation coefficient, was 0.72–0.86 (within-day, 0.72–0.86; between-day, 0.82–0.83). [Conclusion] Ultrasound imaging can be used as a reliable method for measurements of transverse abdominis thickness.