Rehabilitative ultrasound imaging of the supraspinatus muscle: Intra- and interrater reliability of thickness and cross-sectional area

Abstract

Objective: To examine intra- and interrater reliability of thickness and cross-sectional area (CSA) measurements of the supraspinatus muscle using rehabilitative ultrasound imaging (RUSI).

Methods: Two physical therapists acquired b-mode images of the supraspinatus muscles in twenty-five healthy subjects. Thickness and CSA were measured. Intra- and interrater reliability were examined.

Results: Intrarater reliability for thickness was high, (ICC1.1 0.91) for rater 1 and (ICC1.1 0.92) for rater 2. Intrarater reliability for CSA was also high, (ICC1.1 0.90) for rater 1 and (ICC1.1 0.85) for rater 2. Interrater reliability for the thickness was high, (ICC3.1 0.86). For CSA, interrater reliability was moderate, (ICC3.1 0.70).

Conclusion: Supraspinatus muscle thickness and CSA can be reliably measured by physical therapists in healthy subjects. These findings confirm that RUSI has an interesting potential for physiotherapy clinical practice, especially to assess morphometric changes in skeletal muscles. Further research is needed in subjects with shoulder disorders.

Keywords: Morphometry; Rehabilitative ultrasound imaging; Reliability; Sonography; Supraspinatus muscle.