Influence of dominant- as compared with nondominant-side symptoms on Disabilities of the Arm, Shoulder and Hand and Western Ontario Rotator Cuff scores in patients with rotator cuff tendinopathy

Abstract

The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and the Western Ontario Rotator Cuff (WORC) index are 2 widely used patient-reported questionnaires in individuals with rotator cuff (RC) tendinopathy. In contrast to the WORC index, for which the items are specific to the affected shoulder, the items of the DASH questionnaire assess the ability to perform activities regardless of the arm used. The objective of this study is to determine whether scores on the DASH questionnaire and WORC index are affected if the symptoms are on the dominant or nondominant side in individuals with RC tendinopathy. Given the number of items that can be influenced by dominance, the hypothesis is that DASH scores will be impacted by the side of the symptoms. Individuals with RC tendinopathy (N = 149) completed questions on symptomatology and hand dominance, the DASH questionnaire, and the WORC index. Differences in total scores (independent t test) and single items (Wilcoxon rank sum test) were compared between groups of participants with dominant-side symptoms and those without dominant-side symptoms. No significant differences were observed for WORC or DASH total scores when comparing participants with and without symptoms on their dominant side. Single-item comparison revealed more items being affected by symptom side on the DASH questionnaire (6 of 30 items) than on the WORC index (2 of 21 items). The side of the symptoms does not influence the DASH and WORC total scores, as there are no systematic differences between individuals with and without symptoms in their dominant shoulder. However, the presence of dominant symptoms does influence item scores more on the DASH questionnaire than on the WORC index.