Rehabilitative ultrasound imaging of the levator scapula muscle at rest and during contraction: Technical description and reliability
Exercise Science and Sport Managment
BACKGROUND: Altered scapular muscle activity is associated with abnormal scapular motions and shoulder pain. Hence, quantification of these activities is a challenging issue. OBJECTIVES: The purposes of this study were to establish the reliability of measuring levator scapula muscle thickness and to examine how thickness of this muscle changes with contraction. METHODS: Twenty-one asymptomatic individuals (mean age 22.29 ± 2.17 years) participated in this study. Three separate ultrasound images of the levator scapula muscle were captured at the neck-shoulder junction at rest and during a loaded isometric contraction. The procedures were repeated twice, four to seven days apart to establish intra-rater test-retest reliability. Interclass correlation coefﬁcients (ICC) and standard error of measurement (SEM) were used to determine the reliability, and a paired t-test was performed to examine the difference in muscle thickness between two conditions. RESULTS: The results demonstrated that intra-examiner reliability was good at rest (ICC = 0.88, SEM = 1.16 mm) and excellent during loaded isometric contraction (ICC = 0.95, SEM = 0.91 mm). Furthermore, the thickness of levator scapula muscle signiﬁcantly increased from rest to the loaded isometric contraction (Effect size = 1.99, P < 0.001). CONCLUSION: This study demonstrates that the thickness of the levator scapula muscle can be measured reliably at the neck-shoulder junction. Furthermore, ultrasound measures can reliably detect changes in muscle thickness from rest to a contracted state. Therefore, if the need exists to evaluate muscle morphology before and after any treatment strategy, thickness measurement of levator scapula can be determined reliably using ultrasound.
Journal of bodywork and movement therapies
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