The Clinical Problem
Authors: Author 1 Liza Grosman-Rimon PhD.; Author 2 Alasdair Rathbone H.BSc.Kin; Author 3: Brian Vadasz, MSc, Author 4 Dinesh Kumbhare MD MSc
Author 2 University of Western Ontario, Schulich School of Medicine and Dentistry, Authors 1,3 & 4 University of Toronto, Department of Medicine Toronto Rehabilitation Institute-University Health Network
Myofascial pain syndrome is a common pain disorder that currently lacks an imaging gold standard. Ultrasound has been proposed as a candidate to fill this role. However, limited data is available on intra and inter –reliability.
Cross-sectional reliability study
Pain clinic at an academic centre
10 patients with neck pain.
An educational session was provided for the raters. It included the characteristics of the MTrP as described in the literature. Ultrasound of the upper trapezius with independent blinded analysis by two inexperienced and one experienced rater. Each rater examined each US image twice.
Test retest reliability assessments of the US images were performed.
For the detection of a myofascial trigger point: Inexperienced intra-rater Cohen’s kappa were 0.28 to 0.49, inter-rater were -0.13 to 0.18. Experienced intra-rater Cohen’s kappa 0.69.
Inexperienced raters demonstrated poor intra- and inter- rater reliability. Good intra-rater reliability was found in the experienced examiner. If ultrasound is used for the diagnosis of MTrP then it is essential that the clinician receive the appropriate training.