Reliability of Rehabilitative Ultrasound Imaging of the Transversus Abdominis and Lumbar Multifidus Muscles
Abstract
Koppenhaver SL, Hebert JJ, Fritz JM, Parent EC, Teyhen DS, Magel JS. Reliability of rehabilitative ultrasound imaging of the transversus abdominis and lumbar multifidus muscles.
Objectives
To evaluate the intraexaminer and interexaminer reliability of rehabilitative ultrasound imaging (RUSI) in obtaining thickness measurements of the transversus abdominis (TrA) and lumbar multifidus muscles at rest and during contractions.
Design
Single-group repeated-measures reliability study.
Setting
University and orthopedic physical therapy clinic.
Participants
A volunteer sample of adults (N=30) with current nonspecific low back pain (LBP) was examined by 2 clinicians with minimal RUSI experience.
Interventions
Not applicable.
Main Outcome Measures
Thickness measurements of the TrA and lumbar multifidus muscles at rest and during contractions were obtained by using RUSI during 2 sessions 1 to 3 days apart. Percent thickness change was calculated as thicknesscontracted–thicknessrest/thicknessrest. Intraclass correlation coefficients (ICC) were used to estimate reliability.
Results
By using the mean of 2 measures, intraexaminer reliability point estimates (ICC3,2) ranged from 0.96 to 0.99 for same-day comparisons and from 0.87 to 0.98 for between-day comparisons. Interexaminer reliability estimates (ICC2,2) ranged from 0.88 to 0.94 for within-day comparisons and from 0.80 to 0.92 for between-day comparisons. Reliability estimates comparing measurements by the 2 examiners of the same image (ICC2,2) ranged from 0.96 to 0.98. Reliability estimates were lower for percent thickness change measures than the corresponding single thickness measures for all conditions.
Conclusions
RUSI thickness measurements of the TrA and lumbar multifidus muscles in patients with LBP, when based on the mean of 2 measures, are highly reliable when taken by a single examiner and adequately reliable when taken by different examiners.
dDepartment of Physical Therapy/Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
eUS Army-Baylor University Doctoral Program in Physical Therapy, San Antonio, TX
Correspondence to Shane L. Koppenhaver, MPT, 1416 Downington Ave, Salt Lake City, UT 84105
Supported in part by Sonosite Inc, Bothell, WA, by providing the ultrasound machine used in this study at no charge to the Division of Physical Therapy, University of Utah.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.