Reliability of Pressure Pain Thresholds in Healthy Young Adults

Abstract Objectives: The aim of this study was to investigate the inter-rater and intra-rater reliability of pressure pain threshold [PPT] measurements in the supraspinatus muscle tendon, anterior talofibuler ligament, and the extensor digitorum communis muscle belly in healthy young subjects. Methods: A total of 100 healthy undergraduates participated in this study. Two examiners had three trials of measuring the supraspinatus muscle tendon, anterior talofibuler ligament, and extensor digitorum communis muscle belly on the dominant side, which were marked by the first examiner [E1]. Three consecutive measurements were taken with a 60-s interval between trials. The average of three measurements was calculated for each region. After a 60-min interval, the same procedure was repeated by the second examiner [E2] on the same day. Results: Our results indicated that E1 and E2 showed high intra-rater reliability. Significant difference was found between E1 and E2 in anterior talofibular ligament and extensor digitorum communis muscle belly threshold average measurements [p < 0.05], but no significant difference was found at supraspinatus muscle tendon [p > 0.05]. Low significant correlation and reliability was found between E1 and E2 for all measurement sites. Conclusions: Our study results indicated that intra-rater reliability of PPT measurements on tendon, ligament, and muscle belly was high. We found that inter-rater reliability was low in the anterior talofibular ligament and supraspinatus muscle tendon, and adequate in muscle belly. Measurements by one examiner were more reliable than measurements between examiners. This study could be reference for future studies to measure reliability on three different anatomical regions.