An investigation of the reproducibility of ultrasound measures of abdominal muscle activation in patients with chronic non-specific low back pain.
Ultrasound (US) measures are used by clinicians and researchers to evaluate improvements in activity of the abdominal muscles in patients with low back pain. Studies evaluating the reproducibility of these US measures provide some information; however, little is known about the reproducibility of these US measures over time in patients with low back pain. The objectives of this study were to estimate the reproducibility of ultrasound measurements of automatic activation of the lateral abdominal wall muscles using a leg force task in patients with chronic low back pain. Thirty-five participants from an existing randomised, blinded, placebo-controlled trial participated in the study. A reproducibility analysis was undertaken from all patients using data collected at baseline and after treatment. The reproducibility of measurements of thickness, muscle activation (thickness changes) and muscle improvement/deterioration after intervention (differences in thickness changes from single images made before and after treatment) was analysed. The reproducibility of static images (thickness) was excellent (ICC(2,1) = 0.97, 95% CI = 0.96-0.97, standard error of the measurement (SEM) = 0.04 cm, smallest detectable change (SDC) = 0.11 cm), the reproducibility of thickness changes was moderate (ICC(2,1) = 0.72, 95% CI 0.65-0.76, SEM = 15%, SDC 41%), while the reproducibility of differences in thickness changes from single images with statistical adjustment for duplicate measures was poor (ICC(2,1) = 0.44, 95% CI 0.33-0.58, SEM = 21%, SDC = 66.5%). Improvements in the testing protocol must be performed in order to enhance reproducibility of US as an outcome measure for abdominal muscle activation.
Costa
Leonardo Oliveira Pena
LO
The George Institute for International Health, The University of Sydney, Sydney, NSW 2050, Australia. lcos3060@gmail.com
Maher
Chris G
CG
Latimer
Jane
J
Hodges
Paul W
PW
Shirley
Debra
D
D000009:Abdominal Muscles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000328:Adult; D002908:Chronic Disease / Q000517:prevention & control; D004185:Disability Evaluation; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology; D010919:Placebos; D011187:Posture / Q000502:physiology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013131:Spine / Q000503:physiopathology; D014463:Ultrasonography / Q000379:methods
D010919:Placebos