(1) Background: Globally, neck pain is prevalent, affecting around thirty percent of the population annually. To better understand the influence of pain on the myofascial layers, the present study investigated these on the upper trapezius muscle in unilateral, more severe neck pain. (2) Methods: This study was a cross-sectional study. Forty patients (42.2 ± 14.7) with a confirmed diagnosis of unilateral neck pain were examined using durometry and indentometry. This study evaluated the stiffness, elasticity, and pressure pain threshold of both sides of the neck (symptomatic side: SS; healthy side: HS). Furthermore, the range of motion of the cervical spine (lateral flexion, rotation) was quantified using a digital goniometer. (3) Results: A significant lateral discrepancy was observed in stiffness between groups (durometry: SS-33.76 ± 7.78, HS-29.75 ± 7.45, p < 0.001; indentometry: SS-59.73 ± 33.93, HS-4.18 ± 12.69, p = 0.024). In contrast, no differences were found between the comparison sides of the upper trapezius for the parameter's elasticity (SS-0.101 ± 1.09, HS--0.006 ± 0.29, p = 0.416), cervical spine mobility (lateral flexion: SS-37.08 ± 8.15, HS-37.73 ± 7.61, p = 0.559; rotation: SS-73.55 ± 12.37, HS-72.85 ± 11.10, p = 0.660), and algometry (SS-36.41 ± 17.53, HS-37.22 ± 17.00, p = 0.657). (4) Conclusion: Overall, it can be concluded that more severe neck pain unilaterally shows differences in stiffness on the same side. Future research is needed to investigate the links.
Keywords: indentometry; myofascial stiffness; pain pressure threshold; unilateral neck pain.