Background: Ultrasound (US) imaging can be used for the measurement of trunk muscle activity. The displacements of US transducer, especially during more dynamic situations, however, may disturb the measurement results. To control this variable, some studies have used transducer fixator (TF), but no study evaluated the effect of using TF on US reliability in dynamic situations. The present study discriminated this issue.Objective: To investigate the intrasession and intersession reliability of lateral abdominal muscle thickness measurement in dynamic standing postural tasks by using US with and without TF in participants with and without chronic low back pain (CLBP). Design: An intersession and intrasession reliability study. Setting: Biomechanics laboratory, Neuromuscular Rehabilitation Research Center, Semnan University of Medical Sciences, Semnan, Iran. Participants: Twenty-three patients with CLBP and 23 healthy matched individuals. Methods: Abdominal muscle thickness of all the subjects was evaluated with use of US imaging with the patient in the supine position and double-leg stance at different levels of platform stability of BBS (static, levels 6 and 3), with and without using TF. Intraclass correlation coefficients (ICCs), standard errors of measurement, minimal metrically detectable changes, and coefficients of variation were calculated to determine intersession and intrasession reliability of muscle activity measure. Main Outcome Measurements: Lateral abdominal muscle thickness. Results: The intersession ICCs in the conditions with TF ranged from 0.93 to 0.98 and 0.97 to 0.99 in CLBP and healthy individuals, respectively. The intersession ICCs in the conditions without TF ranged from 0.67 to 0.79 and 0.7 to 0.86 in CLBP and healthy groups, respectively. In addition, smaller standard errors of measurement and minimal metrically detectable change values were observed with US measurement in both the groups when TF was used.Conclusion: US imaging appears to have acceptable reliability for the assessment of abdominal muscle thickness during dynamic standing tasks in individuals with and without CLBP. The use of TF results in greater levels of reliability during US measurement of abdominal muscle.
Ehsani, F., Arab, A. M., Salavati, M., Jaberzadeh, S., & Hajihasani, A. (2016). Ultrasound Measurement of Abdominal Muscle Thickness With and Without Transducer Fixation During Standing Postural Tasks in Participants With and Without Chronic Low Back Pain: Intrasession and Intersession Reliability. PM & R, 8(12), 1159-1167. https://doi.org/10.1016/j.pmrj.2016.05.007