Examination of contraction-induced muscle pain as a behavioral correlate of physical activity in women with and without fibromyalgia

Abstract

Purpose: This study aimed to compare muscle pain intensity during a sustained isometric contraction in women with and without fibromyalgia (FM), and examine the association between muscle pain and self-reported levels of physical activity. Methods: Fourteen women with FM and 14 healthy women completed the study, where muscle pain ratings (MPRs) were obtained every 30 s during a 3 min isometric handgrip task at 25% maximal strength, and self-reported physical activity was quantified using the Baecke Physical Activity Questionnaire. Results: Women with FM were less physically active than healthy controls. During the isometric contraction, MPR progressively increased in both groups at a comparable rate, but women with FM generally reported a greater intensity of muscle pain than healthy controls. Among all women, average MPR scores were inversely associated with self-reported physical activity levels. Conclusions: Women with FM exhibit augmented muscle pain during isometric contractions and reduced physical activity than healthy controls. Furthermore, contraction-induced muscle pain is inversely associated with physical activity levels. These observations suggest that augmented muscle pain may serve as a behavioral correlate of reduced physical activity in women with FM.

Implications for Rehabilitation

• Women with fibromyalgia experience a greater intensity of localized muscle pain in a contracting muscle compared to healthy women.

• The intensity of pain during muscle contraction is inversely associated with the amount of physical activity in women with and without fibromyalgia.

• Future studies should determine whether exercise adherence can be improved by considering the relationship between contraction-induced muscle pain and participation in routine physical activity.

• Chronic pain
• exercise
• fibromyalgia
• hyperalgesia

Acknowledgements

We thank Carly Nagel, Michaela Nofsinger and Kelly Santo for their assistance in data collection and processing.

Declaration of interest

This work was supported by a John J. Bonica Fellowship from the International Association for the Study of Pain to MU and a Career Development Award from the Colorado Clinical and Translational Institute (NIHKL2RR025779) to KSM. There is no conflict of interest among the authors.