Craniovertebral Angle and Fibromyalgia Severity

September 7, 2026 updated by: Nadide Koca, Ankara Training and Research Hospital

Evaluation of the Relationship Between Craniovertebral Angle and Fibromyalgia Symptom Severity

Forward Head Posture Frequency in Fibromyalgia Patients Assessed by Craniovertebral Angle: Association with Symptom Severity. Forward head posture is more common in patients with fibromyalgia and is a factor that increases symptom severity.

Study Overview

Status

Recruiting

Detailed Description

Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread musculoskeletal pain, muscle stiffness, joint rigidity, insomnia, fatigue, mood disorders, cognitive dysfunction, anxiety, depression, and general hypersensitivity.

Fibromyalgia is considered a central sensitivity syndrome. Central sensitization refers to a neuronal signal amplification mechanism within the central nervous system that leads to enhanced pain perception. Consequently, patients with FM exhibit an increased receptive field of pain, allodynia, and hyperalgesia.

Headache and temporomandibular disorders (TMD) are among the most common comorbidities in FM, displaying overlapping clinical and pathophysiological features.

Nociplastic pain is defined by the International Association for the Study of Pain as pain arising from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain. The mechanism of nociplastic pain is proposed to involve increased central nervous system sensitization and impaired sensory processing, accompanied by altered pain modulation. Definitive criteria for nociplastic pain have not yet been established. Eight specific disorders associated with central sensitization have been proposed: restless leg syndrome, chronic fatigue syndrome, FM, TMD, migraine or tension-type headache (TTH), irritable bowel syndrome, multiple chemical sensitivities, and whiplash injury.

Central sensitization is classically defined as a consequence of ongoing nociceptive inputs in chronic pain conditions. Its development is reported to be influenced by genetic factors, pain processing disorders in the brain, neuroendocrine and autonomic abnormalities, abnormal cytokines, and immune dysfunction.

As evident, conditions frequently accompanying FM, such as migraine, tension-type headache, chronic fatigue, irritable bowel syndrome, and TMD, share overlapping pathophysiology related to central sensitization.

A bidirectional relationship has been reported between primary headaches and craniocervical postural disorder, defined as Forward Head Posture (FHP). Postural disorders generate nociceptive peripheral stimuli that may lead to sensitization in the trigeminocervical complex.

The trigeminocervical complex (TCC), located in the brainstem, is a common convergence pathway where both trigeminal (dural) and cervical (primarily via the greater occipital nerve) afferent inputs are projected to higher centers in the thalamus and cortex. The TCC serves as the first sensory relay for meningeal and cephalic cutaneous information and forms the pathways for referred pain in primary headaches.

Brainstem interneurons have been shown to play a key role in pain modulation in migraine, TTH, and cluster headaches. Primary headache has been determined to result from trigeminocervical complex dysfunction. Neurophysiological studies on trigeminal reflexes support the concept of primary brainstem dysfunction and central hyperexcitability of trigeminal sensory pathways in chronic pain syndromes such as FM and TTH.

Similarly, animal studies in FM have identified a hyperalgesic state in the trigeminal region.

Sensitization in the trigeminocervical complex can lead to central sensitization by increasing thalamic and cortical stimulation. Peripheral and central sensitization are characterized by widespread hyperalgesia and allodynia. Consequently, patients with chronic primary headache exhibit a larger pain distribution area not only in the craniocervical region but throughout the entire spine.

The relationship between TCC sensitization and pain disorders has been well-documented in human and animal studies. Significant abnormalities in TCC responses have been observed in patients with trigeminal neuralgia, migraine, cluster headache, chronic tension-type headache, and fibromyalgia, attributed to hyperexcitability of trigeminal pathways.

Similarly, TMD, another comorbidity accompanying FM, frequently co-occurs with primary headaches, and the trigeminal system is reported to be the common pathophysiological mechanism.

Forward Head Posture (FHP) refers to the anterior displacement of the head relative to the trunk through upper cervical extension and lower cervical flexion. A craniovertebral angle (CVA) of 49° or less is defined as FHP.

FHP, characterized by forward head projection and rounded shoulders, is a common consequence of modern lifestyles involving prolonged use of laptops, mobile devices, or driving. It leads to persistent headache and is associated with migraine, TTH, and cervicogenic headaches.

The relationship between TMD and FHP is well-established. Forward head posture leads to TMD.

In the pathophysiology of primary headaches and TMD, which frequently accompany FM, the trigeminocervical complex emerges as a factor increasing central sensitization. FHP is reported to be a postural factor contributing to this. Central sensitization also plays a primary role in FM pathophysiology.

Postural studies in FM have reported increased thoracic kyphosis, lower CVA, and impaired cervical joint position sense.

To our knowledge, there are no studies examining the relationship between craniovertebral angle and disease severity in FM. We hypothesize that FHP may play a significant role in central sensitization in FM patients through the trigeminocervical complex, similar to its role in headaches and TMD. Therefore, we aim to investigate the frequency of FHP in FM patients and its relationship with FM disease severity.

Study Type

Observational

Enrollment (Estimated)

134

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Altindag
      • Ankara, Altindag, Turkey (Türkiye), 06230
        • Recruiting
        • Ankara Training and Research Hospital Ankara, Altindag, Turkey, 06230
        • Contact:
      • Ankara, Altindag, Turkey (Türkiye), 06230
        • Completed
        • Department of Physical Therapy and Rehabilitation, University of Health Sciences, Ankara Training and Research Hospital
      • Ankara, Altindag, Turkey (Türkiye), 06230
        • Enrolling by invitation
        • University of Health Sciences, Ankara Training and Research Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Our research will be conducted as a prospective study. The case group will consist of male and female patients aged 18-55 years who present to the Physical Medicine and Rehabilitation clinic with widespread pain complaints and are diagnosed with Fibromyalgia (FM) according to ACR 2010 diagnostic criteria. The control group, matched for age and gender distribution, will be selected from patients presenting with mechanical knee pain complaints and no cervical symptoms. Considering the increased likelihood of degenerative changes in the cervical region with advancing age, the investigators limited the upper age limit to 55 years.

Demographic data will be collected through face-to-face interviews during examination. During this time, patients will complete the Fibromyalgia Impact Questionnaire (FIQ). The FIQ is a 10-item questionnaire that evaluates the severity of fibromyalgia symptoms.

Description

Inclusion Criteria:

  • Aged 18-55 years
  • Diagnosed with Fibromyalgia (FM) according to The American College of Rheumatology (ACR) 2010 Diagnostic Criteria for Fibromyalgia

Exclusion Criteria:

  • History of past or current pathology in the cervical spine, thoracic spine, or upper extremities
  • History of paraspinal or thoracic surgery involving the head, spine, or shoulders within the last six months
  • Structural spinal malformation
  • History of surgical or neurological disorders
  • Cervical trauma or pain treatment within the last 6 months
  • Temporomandibular surgery
  • Psychiatric disorders (e.g., dementia, amnesia, or delirium)
  • Systemic inflammatory rheumatic diseases

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Fibromyalgia Group
Fibromyalgia (FM) is a chronic pain syndrome characterized by widespread musculoskeletal pain, muscle stiffness, joint stiffness, insomnia, fatigue, mood disorders, cognitive dysfunction, anxiety, depression, and general sensitivity. Female and male patients between the ages of 18-55 who are diagnosed with FM according to the ACR 2010 diagnostic criteria will constitute the case group.
Control Group
The control group, matching similar age and gender distribution, will be selected from patients presenting with mechanical knee pain complaints and without neck complaints. Considering the increased likelihood of degenerative changes in the cervical region with advancing age, the investigators limited the upper age limit to 55.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The craniovertebral angle
Time Frame: up to 12 weeks
During the same visit, permission will be obtained from patients for photography, and it will be explained that the photograph will be used solely for scientific research. One lateral photograph will be taken from consenting patients. For this purpose, the patient will be instructed to assume a standing posture and then relax. After the photographs taken with the camera placed at shoulder level are printed, the craniovertebral angle representing the forward head posture will be measured. The craniovertebral angle is the angle between the horizontal line passing through the 7th cervical vertebra and the line connecting the tragus of the ear to the C7 spinous process. The craniovertebral angle value will be calculated as the average value measured 5 times.
up to 12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Fibromyalgia Impact Questionnaire
Time Frame: up to 12 weeks
The Fibromyalgia Impact Questionnaire (FIQ) consists of 10 items. The first item contains 11 questions related to physical function - each question is rated on a 4-point Likert-type scale. Items 2 and 3 ask the patient to mark the number of days they felt well and the number of days they could not work (including housework) due to fibromyalgia symptoms. Items 4 through 10 are horizontal linear scales marked in increments of 10 on which the patient rates work difficulty, pain, fatigue, morning tiredness, stiffness, anxiety, and depression. The highest possible score for each of the 10 items is 10, thus the highest possible score is 100. The average FM patient scores approximately 50 points; severely affected patients typically score ≥70 points.
up to 12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Nadide Koca, M.D., Ankara Training and Research Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 1, 2025

Primary Completion (Estimated)

November 1, 2026

Study Completion (Estimated)

November 1, 2026

Study Registration Dates

First Submitted

April 27, 2025

First Submitted That Met QC Criteria

April 27, 2025

First Posted (Actual)

May 5, 2025

Study Record Updates

Last Update Posted (Actual)

September 9, 2026

Last Update Submitted That Met QC Criteria

September 7, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe