Upper Trapezius Changes Linked to Fibromyalgia

This study reveals that muscle changes in Fibromyalgia can be seen in ultrasounds and that upper trapezius changes are linked to Fibromyalgia.

Fibromyalgia (FM) is a long-term condition that causes widespread muscle pain, fatigue, sleep problems, and memory issues. It affects about 2–3% of people globally. The exact causes of FM are still not well understood, but both genetic and environmental factors seem to contribute. 

Recent research suggests that central sensitization—a condition where the nervous system becomes overly sensitive to pain—plays a role in FM.

In the past, FM has been diagnosed using tender points on the body. Studies have shown that muscles in these areas may have poor blood flow and signs of damage related to low oxygen levels. One muscle often affected is the upper trapezius (the muscle along the back of the neck and shoulders).

* Trapezius muscle * Original by sv:Användare:Chrizz

Use of Ultrasound in FM:
Ultrasound is a safe and noninvasive tool used to examine muscles. Newer methods like blob analysis can give more detailed images of muscle structure. Blob analysis looks at clusters of similar signals (called "blobs") in the muscle, helping to detect structural changes that might not be visible with standard imaging.

While blob analysis has been used to study other muscle conditions, it hasn’t been used before to assess muscles in FM patients. 

This study aims to fill that gap by examining the upper trapezius muscle using B-mode ultrasound and blob analysis in FM patients compared to healthy individuals.

Methods:
The study included 34 women with FM and 34 healthy women. Participants were evaluated using several scales to measure pain, fatigue, mental health, and quality of life. 

Ultrasound images of the upper trapezius muscle were taken and analyzed using blob analysis software to measure blob size, count, and brightness (echointensity).

Key Findings:

• FM patients had larger and more numerous blobs in the upper trapezius muscle compared to healthy individuals.

• Higher echointensity (brighter muscle areas) was found in FM patients.

• Blob size and count were linked to higher pain, fatigue, and central sensitization scores.

• These structural muscle changes could help explain ongoing pain and sensitivity in FM.

Conclusion:
This study is the first to use blob analysis with ultrasound to examine muscle changes in FM. 

The results suggest that FM is associated with measurable structural muscle changes, particularly in areas of pain. This technique may offer a more objective way to assess FM and understand its underlying mechanisms.

Source:

Structural changes in the upper trapezius muscle of fibromyalgia patients identified by quantitative ultrasonography: a cross-sectional study
Observational Research | Open access | Published: 22 April 2025