Ultrasound imaging (USI) has been shown to be a reliable measure for direct assessment of the lumbar multifidi among younger adults. However, given age- and chronic low back pain (CLBP)-related spinal changes, similar studies are needed before clinical use of USI among older adults with CLBP. The goals of this study were to evaluate intra- and interexaminer reliability for USI assessment of multifidi thickness at rest and during a contraction and to determine standard error of measurement values (SEMs) and minimal detectable change values (MDCs) among older adults with CLBP.
Thirty-one adults, aged 60 to 85 years, with CLBP were recruited. Two examiners performed USI assessments of multifidus thickness at rest and during a contralateral lower extremity lift. Intraclass correlation coefficients (ICCs) were used to estimate inter- and intraexaminer reliability. Additionally, SEMs and MDCs were calculated.
All USI measurement techniques demonstrated excellent within-day, interexaminer procedural reliability (ICCs: 0.82-0.85) and good-to-excellent between-day, interexaminer procedural reliability (ICCs: 0.72-0.79). The SEMs ranged from 0.36 to 0.46 cm; MDCs ranged from 1.01 to 1.26 cm. Regardless of the measurement technique, examiner 1, the more experienced examiner, demonstrated lower SEMs and MDCs than examiner 2.
Lower ICCs, greater SEMs, and greater MDCs for USI multifidus thickness assessment in older adults with CLBP, when compared with previously published, procedural reliability results for younger adults with and without low back pain, may indicate that imaging is more challenging in this patient population. Factors, such as examiner training and participant anthropometrics, may impact reliability.
Good-to-excellent intra- and interexaminer USI procedural reliability may provide clinicians a direct assessment technique for clinical evaluation of the lumbar multifidi in older adults with CLBP. SEMs and MDCs may allow for accurate interpretation of USI assessments in this population.
1Department of Physical Therapy, University of Delaware, Newark, Delaware.
2Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Ft Detrick, Maryland.
Address correspondence to: J. Megan Sions, PT, DPT, PhD, OCS, at 540 South College Avenue, Suite 144A, University of Delaware, Newark, DE 19713 (email@example.com).
The work of Dr. Sions is supported in part by the Foundation for Physical Therapy PODS I/II, the University of Delaware's Office of Graduate Studies, R21HD057274 (NICHD), and R01AG041202-01 (NIA). The work of Teonette Velasco and Dr. Hicks is supported in part by R21 HD057274 (NICHD) and R01AG041202-01 (NIA).
A portion of this article was presented in poster format at the 2011 Orthopedic Research Society Meeting in Long Beach, California.
The views expressed herein are those of the authors and do not reflect the official policy or position of the U.S. Army Medical Research and Materiel Command, the U.S. Army Medical Department, the U.S. Army Office of the Surgeon General, the Department of the Army, Department of Defense, or the U.S. Government.
The authors declare no conflicts of interest.
Robert Wellmon was the Decision Editor.