Reliability of Ultrasound Findings in Patients with Lumbar Multifidus Myofascial Pain Syndrome.

Abstract

Lumbar multifidus muscle provides stability to the spine. The present study aimed to evaluate the reliability of ultrasound findings in patients with lumbar multifidus myofascial pain syndrome (MPS). A total of 24 cases (7 females, 17 males, mean age: 40.13± 5.69, BMI: 26.48±4.96) with multifidus MPS were assessed. The variables were muscle thickness in rest and contraction, thickness changes, and cross-sectional area (CSA) in rest and contraction. Two examiners performed the test and retest sessions. The active trigger points of lumbar multifidus on the right and left side of the cases were 45.8 % and 54.2%, respectively. The intraclass correlation coefficient (ICC) values for muscle thickness and thickness changes showed moderate to very high reliability for both within and between intra-examiner measurements. (ICC, 1st examiner: 0.78-0.96; ICC, 2nd examiner: 0.86-0.95). In addition, the ICC values of within and between-session intra-examiner for CSA were high. (ICC, 1st examiner: 0.83-0.88; ICC, 2nd examiner: 0.84-0.89). The ICC and standard error of measurement (SEM) of inter-examiner reliability ranged between 0.75 to 0.93 and 0.19 to 0.88 for multifidus muscle thickness and thickness changes. The ICC and SEM of inter-examiner reliability ranged between 0.78 to 0.88 and 0.33 to 0.90 for CSA of the multifidus muscle. The within and between-session reliability of multifidus thickness, thickness changes, and CSA was moderate to very high in patients with lumbar MPS when taken by two examiners. Furthermore, the inter-examiner reliability of these sonographic findings was high.