Intra-tester og inter-tester reliabilitet av senetykkelsesmåling med diagnostisk ultralyd hos pasienter med skuldertendinopati

Background and purpose: Shoulder tendinopathy is a common reason for shoulder pain and represents a great socioeconomic burden. Ultrasonography is used increasingly in primary care. In order to apply clinical measurement instruments optimally, it is important to investigate their reliability. The purpose of this study was to investigate inter-, and intra-tester reliability of ultrasonographic measurements of tendon thickess in supraspinatus and biceps brachii. Research question: What is the inter-tester, and intra-tester reliability of ultrasonographic measurements of tendon thickess in supraspinatus and biceps brachii caput longum in a population with shoulder tendinopathy? Methods: A quantitative reliability study with a non-experimental design was performed. Ultrasonographic measurement of the tendon thickness in supraspinatus and biceps brachii was undertaken on participants with shoulder tendinopathy (N = 27). Analysis of inter-tester reliability was based on tendon thickness measurements from two raters. Intra-tester reliability analysis was performed on two sets of data from one rater. Intraclass correlation coefficients ICC1,1 and ICC3,1 was utilized for analysis of relative reliability. Within- subject standard deviation was utilized in analysis of absolute reliability. Results: Relative reliability for biceps brachii was very good in five of seven analyses (range ICC: 0,81 - 0,94), and good in two of seven (range ICC: 0,64 - 0,65). The results for supraspinatus showed moderate reliability in two of seven analyses (range ICC: 0,52 - 0,54), four indicated good reliability (range ICC: 0,63 - 0,79) and one showed very good reliability (ICC: 0,90). Conclusion: The results indicate a very good reliability for biceps brachii and a good reliability for supraspinatus in measuring tendon thickness with ultrasonography