Relationship Between Intensity of Neck Pain and Disability and Shoulder Pain and Disability in Individuals With Subacromial Impingement Symptoms: A Cross-Sectional Study.

OBJECTIVE: This study aimed to verify a possible relationship between shoulder disability and shoulder pain intensity and the variables related to cervical-spine dysfunction, and determine which of these can differentiate moderate to severe shoulder pain (>4 on a numerical rating scale [NRS]) from mild shoulder pain (≤4 on the NRS) in individuals with subacromial impingement symptoms. METHODS: One hundred and forty volunteers with shoulder pain were evaluated. Demographic information and variables related to the shoulder and neck were collected. Self-reported pain and disability of the shoulder and cervical spine were measured using the Shoulder Pain and Disability Index (SPADI) and Neck Disability Index (NDI) questionnaires, respectively. An NRS was used to measure pain in the shoulder and cervical spine. A purposeful modeling strategy was used to determine the best model to predict shoulder disability and shoulder pain (dependent variables). Multiple logistic regression analysis followed by receiver operating curve analysis was used to determine which variables better differentiated moderate to severe shoulder pain from mild shoulder pain. RESULTS: Variables such as Neck Disability Index (NDI) score (ß = 1.09, P = .00) and age (ß = -0.19, P = .03) were associated with the total SPADI score. Neck pain was significantly associated with shoulder pain (ß = 0.40, P = .00). The combination of variables predicting moderate to severe shoulder pain was total SPADI score (odds ratio [OR] = 1.15, P = .003), neck pain (OR = 3.20, P = .04), and age (OR = 1.01, P = .05). CONCLUSION: Our results demonstrate the important connection between shoulder- and neck-related symptoms in individuals with subacromial impingement symptoms.