Publications

• Objective assessment of trapezius muscle viscoelasticity using handheld myotonometry can help clinicians identify segment-specific mechanical alterations associated with chronic neck pain.
• Routine integration of myotonometric assessment in clinical practice could enhance the precision of physiotherapy evaluation and monitoring in patients with chronic neck pain.

Background: Chronic neck pain (CNP) is associated with altered muscle properties and pain sensitivity, especially in the trapezius muscle. However, evidence on how viscoelastic properties vary across different regions of the trapezius remains limited.

Objective: This study aimed to compare the viscoelastic properties, pressure pain threshold, cervical range of motion, disability, depression, and perceived stress between individuals with CNP and asymptomatic controls.

Methods: Twenty-six individuals with CNP (median age (IQR): 23 (22 – 24)) and 26 age- and sex-matched controls (median age (IQR): 23 (22 – 25)) were included. Muscle viscoelastic properties of the upper, middle, and lower trapezius were measured using the MyotonPRO. Pressure pain threshold was evaluated with a digital algometer, and cervical range of motion was assessed using a CROM device. Disability, depression, and perceived stress were measured using the Neck Disability Index, Beck Depression Inventory, and Perceived Stress Scale, respectively.

Results: Individuals with CNP showed significantly increased muscle tone and stiffness in the upper trapezius bilaterally and altered viscoelastic properties in the middle trapezius (affected side). Pressure pain threshold values were significantly lower across all portions of trapezius. Despite these differences, no significant cervical range of motion limitations were found.

Conclusion: Altered mechanical and sensory properties in the trapezius muscle – particularly in its upper and middle portions – may contribute to CNP, even in the absence of substantial cervical mobility limitations. This study provides the first comprehensive comparison of all three trapezius regions in individuals with CNP using handheld myotonometry, offering novel insights into the segment-specific mechanisms underlying chronic neck pain.

Keywords: elasticity imaging techniques, neck disability, neck pain, pressure pain threshold, trapezius muscles

In conclusion, individuals with CNP exhibited increased muscle stiffness and reduced viscoelastic deformation in the upper portion of trapezius bilaterally. Notably, in the middle trapezius, the affected side showed heightened stiffness and decreased viscoelastic deformation. Additionally, these individuals demonstrated significantly increased pain sensitivity bilaterally in the upper, middle, and lower portions of the trapezius muscle compared to asymptomatic controls. However, these alterations in pain sensitivity and viscoelastic properties of the trapezius muscle did not translate into significant differences in cervical ROM. These findings suggest that altered mechanical and sensory properties of the trapezius muscle may play a more prominent role in the symptomatology of CNP than limitations in cervical range of motion, highlighting the importance of targeted myofascial and neuromuscular interventions in rehabilitation strategies.