Psychological and Physical Risk Factors for Pressure Pain Hypersensitivity of the Upper Trapezius in Food Service Workers With Nonspecific Neck/shoulder Myofascial Pain

Objectives: It is unclear which factors increase the risk of developing pressure pain hypersensitivity, a type of neurophysiological hyperexcitability. The present study investigated the relative contributions of physical and psychological factors to pressure pain hypersensitivity of the upper trapezius for each sex. Methods: In total, 154 individuals with neck/shoulder myofascial pain participated, among 372 food service workers. Participants completed a questionnaire (age, sex, Beck Depression Inventory, and Borg Rating of Perceived Exertion scale) and then were photographed to measure posture. Pressure pain sensitivity, two range of motions (cervical lateral-bending and rotation), and four muscle strengths (serratus anterior, lower trapezius, biceps, and glenohumeral external rotator) were measured by a pressure algometer, iPhone application, and handheld dynamometer. For each sex, forward multivariate logistic regression was used to test our a priori hypothesis among selected variables that a combination of psychosocial and physical factors contributed to the risk for pressure pain hypersensitivity. Results: : In multivariate analyses, lower trapezius strength (odds ratio = 0.94, 95% confidence interval = 0.91–0.97, p = 0.001) was the only significant risk factor for pressure pain hypersensitivity in men. Dominant painful ipsilateral cervical rotation range of motion (odds ratio = 0.96, 95% confidence interval = 0.92–0.99, p = 0.037) was the only risk factor for pressure pain hypersensitivity in women. Discussion: Lower trapezius strength and dominant painful ipsilateral cervical rotation range of motion could serve as guidelines for preventing and managing pressure pain hypersensitivity of the upper trapezius in food service workers with nonspecific neck/shoulder myofascial pain. Trial registration: Research Information Service (CRIS) under the code KCT0002810 (granted on 20/04/2018) and the registration timing was retrospective.