A pilot study using ultrasound imaging to compare fascial thickness between chronic neck pain and control groups

Abstract

BACKGROUND: ‘Densification’, defined as a thickening in the loose connective tissue (LCT) of fascia, is a recently proposed theory that is thought to be associated with chronic neck pain (CNP). Stecco and colleagues reported that individuals with CNP have a greater thickness of deep cervical fascia enveloping the sternocleidomastoid (SCM) when compared to asymptomatic controls. Due to a number of limitations these findings are exploratory and require further validation. Before larger more definitive studies can take place, a pilot study is required to estimate an effect size between groups (symptomatic and control) and inform an appropriate sample size.

PURPOSE: The current pilot study aims to use ultrasound imaging (USI) to measure the thickness of the deep cervical fascia enveloping SCM and upper Trapezius (uTrap) in controls and people with CNP.

METHODS: In each of the 18 participants, pre-established USI protocols were used to measure the fascial thickness of SCM and uTrap in CNP (n = 9) and control (n = 9) groups.

RESULTS: Between groups there were no significant differences in fascial thickness for SCM and uTrap. The effect for detecting differences in fascial thickness between CNP and controls was ‘small’ for SCM and ‘medium’ for uTrap.

CONCLUSION: Overall, there were no differences in fascial thickness between CNP and controls. Using these results and the identified effect sizes, almost 800 participants would be required to sufficiently power a study examining fascial thickness between people with CNP and asymptomatic controls. This pilot study identified additional limitations, such as variations in fascial morphology, that should be considered by future studies into fascial thickness.