Strength Assessment Under Dual Task Conditions in Women with Fibromyalgia: A Test–Retest Reliability Study

The present study aimed to: (1) analyze the test–retest reliability of the 30 s chair stand test and the 30 s arm curl test under dual-task conditions; (2) analyze the test–retest reliability of a new variable which assesses the total performance (cognitive + physical) in both tests. A total of 37 women with fibromyalgia participated in the study. Participants completed the 30 s arm curl test and 30 s chair stand test in both simple and dual-task conditions. These tests were repeated after seven days. In the 30 s chair stand dual-task test the reliability was low to good whereas that of the total performance variable was low to moderate. The reliability in both the 30 s arm curl dual-task test and the total performance variable were good to moderate. Both the 30 s chair stand test and 30 s arm curl test under dual-task conditions and the total performance variables had good test–retest reliability. However, it is necessary to consider the fluctuations of the intraclass correlation coefficient (ICC).