Pain-related fear phenotypes are associated with function of the upper limbs in individuals with shoulder pain

Objective: To identify and describe phenotypes related to kinesiophobia, fear-avoidance, and pain catastrophizing, and determine clinical and demographic characteristics related to each phenotype as a function of self-reported function of the upper limbs in individuals with shoulder pain.

Methods: One hundred and seventy-seven individuals with shoulder pain participated in this study. Tampa Scale of Kinesiophobia, Fear-Avoidance Beliefs Questionnaire, Pain Catastrophizing Scale, Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH), Numerical Pain of Rating Scale, and the angular onset of pain during the elevation of the arm were measured in all participants. A cluster analysis was performed considering kinesiophobia, fear-avoidance, and pain catastrophizing, then clinical and demographic characteristics of clusters were used to model individual's chance to belong to one of the clusters as a function of DASH.

Results: Two clusters were identified based on kinesiophobia, fear-avoidance, and pain catastrophizing. The cluster with worse pain-related fear profile presented (p < 0.05) higher age, worse function, and higher pain intensity. This same cluster was also associated with involvement of the dominant side (OR = 2.10, 95% CI = 1.03, 4.41) and worse function (OR = 0.96, 95% CI = 0.94, 0.98).

Conclusion: This study identified that individuals with worse pain-related fear profile were older, with worse function, and higher pain intensity. Worse function and involvement of the dominant side were associated with the phenotype with a worse pain-related fear condition.