Intra-rater reliability of transversus abdominis measurement by a noviceexaminer: Comparison of freehand to probe force device method of real-time ultrasoundimaging

摘要

A “free hand” real-time-ultrasound method is commonly applied to measure transversusabdominis. Potentially, this increases transversus abdominis measurement error due touncontrolled variability in probe to skin force, inclination, and roll, particularly fornovice examiners. This single-group repeated-measures reliability study compared theintra-rater reliability of transversus abdominis thickness and activation measurement by anovice examiner between free hand and a standardized probe force device method. Theexaminer captured ultrasound videos of transversus abdominis in a single session inhealthy participants (n =  33). Free hand ultrasound featureduncontrolled probe force, inclination, and roll, while probe force device methodultrasound standardized these parameters. Images of transversus abdominis at rest andcontracted were measured and transversus abdominis activation calculated. Intraclasscorrelation coefficient, coefficient of variation, standard error of measurement, andworthwhile differences were calculated. The probe force device method resulted in greaterreliability (intraclass correlation coefficient = 0.75–0.96) and lower measurement error(coefficient of variation = 8.89–28.7%) compared to free hand (intraclass correlationcoefficient = 0.63–0.93; coefficient of variation = 6.52–29.4%). Reliability was good forall measurements except free hand TrA-C, which was moderate. TrA-C had the lowestreliability, followed by contracted thickness of the transverse abdominis, with restingthickness of the transverse abdominis being highest. Worthwhile differences were lowerusing a probe force device method versus free hand for resting thickness of the transverseabdominis and contracted thickness of the transverse abdominis and similar for TrA-C.Standardization using probe force device method ultrasound to measure transversusabdominis improved intra-rater reliability in a novice examiner. Use of a probe forcedevice method is recommended to improve reliability through reduced sources of measurementerror. Probe force device method intra- and inter-rater reliability in examiners ofvarying experience, in clinical populations, and to visualize other structures meritsexploration.