Comparison between the Impacts of Memory and Arithmetic-Based Dual Tasks on Physical Performance in Women with Fibromyalgia

SIMPLE SUMMARY: This article focuses on comparing two types of cognitive tasks (memory or arithmetic) while performing a physical task. The application of two simultaneous tasks is known as the dual-task paradigm. In fibromyalgia, its analysis has become of great interest since most of the activities of daily living involve physical and cognitive tasks that are impaired in this disease. The physical fitness tests chosen for this study took into account the flexibility, strength, and movement patterns involved in activities of daily living. The simultaneous cognitive tests were: (1) Immediately before the test, three random words had to be memorized by participants, and immediately after the test these words had to be recalled aloud (memory task); and (2) counting aloud backward in rows of two, starting from a random number between 50 and 100 (arithmetic task). The results showed that the arithmetic task had a more significant impact on physical performance than the memory task on the upper-extremity flexibility and lower-extremity strength of women with fibromyalgia. In addition, cognitive performance was lower in the arithmetic- than in the memory-based task. The characteristics of the sample, environment, complexity of the motor task, and difficulty of the simultaneous cognitive task may also be relevant for understanding the differences in interference caused by the two types of cognitive task (arithmetic or memory). ABSTRACT: Background: Fibromyalgia symptoms have a significant impact on the ability to perform activities of daily living. These activities require the ability to perform two or more tasks at the same time, which is known as a dual task. Purpose: To analyze physical and cognitive performance differences between memory and arithmetic dual tasks. Methods: Twenty-five women with fibromyalgia participated in this study. Participants performed three physical tests (back scratch, arm curl, and 10-step stair) as a single task and under two types of dual task (memory and arithmetic). Results: Differences between the single and dual tasks were observed in the back scratch and the 10-step stair tests using the arithmetic dual-task. Significant differences were only observed for the memory dual-task in the 10-step stair test. In addition, the performance in the back scratch and in the 10-step stair was significantly lower under the arithmetic compared to the memory-based dual task. Furthermore, a significant difference between these two types of dual task was obtained in the dual-task cost of 10-step stair. Regarding cognitive performance, a significantly lower percentage of correct responses was found in the AbDT compared to the MbDT in the 10-step stair test. Conclusions: the AbDT could have a higher impact on physical performance than the MbDT during the back scratch and the 10-step stair tests. The characteristics of the sample, environment, complexity of the motor task, and difficulty of the simultaneous cognitive task may also be relevant for understanding the differences in dual-task interference.