Chronic Pain Associated With Significantly Reduced Ability to Relax Muscles

A study found that participants with moderate or severe chronic pain had a significantly reduced ability to relax their muscles compared with those reporting minimal or no chronic pain.1

“The results of this study may have value for clinical practice by increasing the attention, awareness, and evidence of the ability to relax muscles and highlight that clinical bodily findings among individuals with chronic pain should guide the choice of treatment,” wrote investigator Live Førland Havstad, PhD Candidate, from Norwegian University of Science and Technology, and colleagues.

Clinicians commonly assess muscle tension by evaluating a patient’s ability to relax through flexibility testing and passive range-of-motion maneuvers. Clinicians may measure muscle displacement, force, and stiffness.2

Empirical evidence characterizing muscle tension in patients with chronic pain remains limited. Thus, investigators compared the ability to relax muscles in individuals with and without chronic pain, as well as in those with fibromyalgia and chronic tension-type headache, versus other chronic pain conditions.1

The team analyzed data from the HUNT Pain Examination Study, which included 551 individuals from the general Norwegian population. Based on clinical assessments by physicians and physiotherapists, 399 participants had chronic pain of at least moderate severity, while 152 had no chronic pain. Among those with chronic pain, 57 had fibromyalgia, and 23 had chronic tension-type headache.

Investigators evaluated muscle relaxation using the Global Physiotherapy Examination (GPE), which assesses flexibility and passive movement. Investigators performed multiple linear regression analyses to examine associations between chronic pain status and the ability to relax muscles.

Results showed that participants with moderate to severe chronic pain had significantly poorer muscle relaxation, reflected by reduced flexibility (P < .001) and impaired passive movements (P < .001), compared with those with minimal or no chronic pain. Gender, age, and chronic pain status accounted for 23% of the variance in flexibility and 15% of the variance in passive movements. Women demonstrated a greater ability to relax their muscles than men. Further analyses demonstrated reductions in flexibility and passive movements among participants with fibromyalgia (P <.001) and chronic tension-type headache (P =.027) compared with those with other chronic pain conditions.

The team noted the absence of a clear definition for what constitutes a normal ability to relax muscles. In prior research, GPE testing in healthy individuals who struggled with muscle relaxation helped distinguish deviations from an “ideal” ability versus a normal range. The investigators emphasized the need to establish normative ranges and clinically meaningful thresholds, which could inform decisions about whether improving muscle relaxation should serve as a treatment target.

Investigators acknowledged several limitations, including the use of the broad term of flexibility. In this study, flexibility represented the participant’s ability to relax muscles, but the term also captures joint mobility and may relate to limitations in connective tissue elasticity involving joint capsules, tendons, and ligaments. Age-related changes in joint mobility further complicate interpretation, making it difficult to determine whether reduced flexibility stemmed from biomechanical joint constraints, impaired muscle relaxation, or both.

Additional limitations included an older sample (mean age, 63 years) and potential bias from subjective assessments conducted by multiple examiners, without intra-examiner reliability testing. The findings were also influenced by the HUNT study’s 52% participation rate. Participants were drawn from HUNT-3, which included lower proportions of men, younger individuals, and those with lower socioeconomic status, along with higher rates of musculoskeletal pain and headache.

“The findings reveal a significant reduction in the ability to relax muscles during clinical testing in these patient groups,” investigators concluded. “This contribution from the general population provides insights into an area often studied within patient populations, underlining the importance of relaxation techniques as a component in the management of chronic pain.”

References

1. Havstad LF, Glette M, Landmark T, Butler S, Woodhouse A. The Ability to Relax Muscles in Chronic Pain Conditions in the General Population: A Cross-Sectional Study (The HUNT Pain Examination Study). Physiother Res Int. 2026;31(1):e70131. doi:10.1002/pri.70131

2. Davidson MJ, Nielsen PMF, Taberner AJ, Kruger JA. Is it time to rethink using digital palpation for assessment of muscle stiffness?. Neurourol Urodyn. 2020;39(1):279-285. doi:10.1002/nau.24192