Publications
Changes in the mechanical properties and pressure pain thresholds of muscles in patients with fibromyalgia and their relationship with clinical parameters: a case-control study
Authors: Dilek Hande Esen 1, Serkan Tas 2, Mehmet Eroglu 3
Affiliations:
- Department of Therapy and Rehabilitation, Vocational School of Health Services, Toros University, 33140 Mersin, Turkey
- Department of Physical Therapy and Rehabilitation, Faculty of Health Sciences, Toros University, 33140 Mersin, Turkey
- Department of Physical Medicine and Rehabilitation, VM Medical Park Hospital, 33110 Mersin, Turkey
Journal: European Journal of Applied Physiology - June 2026 (DOI: 10.1007/s00421-026-06281-y)
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Field & Applications:
- Medical
- Rheumatology
- Women's health
Myoton Clarification Note: A Guide to Interpreting the Inverse Relationship Between Logarithmic Decrement and Tissue Elasticity
Purpose: The association between fibromyalgia and changes in muscle mechanical properties is unclear. The primary objective of this study was to compare the mechanical properties (tone, stiffness, and elasticity) of the upper trapezius (UT), extensor carpi radialis brevis (ECRB), and medial gastrocnemius (MG) muscles between patients with fibromyalgia (PwFM) and healthy controls. The secondary objective was to investigate the association between muscle mechanical properties and relevant clinical parameters.
Methods: Twenty-nine women and two men with fibromyalgia, and 31 age-matched healthy controls were included in this study. Muscle mechanical properties were assessed using myotonometry (MyotonPRO®), pressure pain thresholds (PPTs) with a digital algometer (Commander Echo-Algometer®), pain intensity using a visual analog scale, and disease impact using the Revised Fibromyalgia Impact Questionnaire.
Results: Muscle frequency (tone) and dynamic stiffness in the UT, ECRB, and MG were significantly higher in the PwFM group compared to controls (p < 0.05). Effect sizes were strong for the UT (|r|≥0.5), weak to moderate for the ECRB (|r|=0.293–0.306), and weak for the MG (|r|=0.293). No significant between-group differences were observed in logarithmic decrement (elasticity) (p > 0.05). In the PwFM group, a moderate positive correlation was found between the frequency of the MG muscle and its PPT (r = 0.508, p = 0.003).
Conclusion: The present study revealed that the tone and stiffness of the UT, ECRB, and MG muscles were increased in PwFM. These findings indicate that altered muscle mechanical properties were associated with fibromyalgia and may warrant consideration in future research exploring clinical management approaches.
Keywords: fibromyalgia syndrome, stiffness, tone, elasticity, pain sensitivity
The current study revealed increased tone and stiffness in the UT, ECRB, and MG muscles of PwFM, along with a significant reduction in PPT values. These findings suggest that fibromyalgia is not limited to subjective symptoms but may involve alterations in the passive mechanical properties of muscle tissue and pain sensitivity. The results highlight the importance of considering muscle mechanics and mechanical sensitivity in the diagnosis and management of fibromyalgia, and suggest that interventions targeting muscle relaxation, alongside pain control, may offer clinically meaningful benefits.