Background: It has been reported that manipulative therapy directed at the cervical and thoracic spine may improve outcomes in patients with shoulder pain. To date, limited data are available to help physical therapists determine which patients with shoulder pain may experience changes in pain and disability following the application of these interventions.
Objective: The purpose of this study was to identify prognostic factors from the history and physical examination in individuals with shoulder pain who are likely to experience rapid improvement in pain and disability following cervical and thoracic spine manipulation.
Design: This was a prospective single-arm trial.
Setting: This study was conducted in outpatient physical therapy clinics.
Participants: The participants were individuals who were seen by physical therapists for a primary complaint of shoulder pain.
Intervention and measurements: Participants underwent a standardized examination and then a series of thrust and nonthrust manipulations directed toward the cervicothoracic spine. Individuals were classified as having achieved a successful outcome at the second and third sessions based on their perceived recovery. Potential prognostic variables were entered into a stepwise logistic regression model to determine the most accurate set of variables for prediction of treatment success.
Results: Data for 80 individuals were included in the data analysis, of which 49 had a successful outcome. Five prognostic variables were retained in the final regression model. If 3 of the 5 variables were present, the chance of achieving a successful outcome improved from 61% to 89% (positive likelihood ratio=5.3).
Limitations: A prospective single-arm trial lacking a control group does not allow for inferences to be made regarding cause and effect. The statistical procedures used may result in "overfitting" of the model, which can result in low precision of the prediction accuracy, and the bivariate analysis may have resulted in the rejection of some important variables.
Conclusions: The identified prognostic variables will allow clinicians to make an a priori identification of individuals with shoulder pain who are likely to experience short-term improvement with cervical and thoracic spine manipulation. Future studies are necessary to validate these findings.
Trial registration: ClinicalTrials.gov NCT00835302.