The point prevalence of shoulder symptoms has been reported to range from 20-33% and the incidence of shoulder complaints in the general population is increasing. Furthermore, several authors have reported low rates of perceived recovery (patient reports of "being cured") for patients with a new episode of shoulder or neck pain.3-6 According to Bot et al, less than 25% of patients with a first episode of shoulder pain reported recovery after 3 months, and only 32% stated they had recovered (no longer had symptoms) after 1 year. Other studies have investigated the prognosis of shoulder pain in general practice. Croft et al reported recovery rates of only 21% after 6 months and 49% after 18 months. Van der Windt et al and Winters et al reported recovery rates of 51% and 59% after 12 to 18 months, respectively. Finally, Rekola et al reported that 25% of patients with shoulder or neck pain experienced at least one episode of recurrence within 12 months. These findings suggest that shoulder pain can be recurrent and frequently progresses to the chronic stage.

The Guide to Physical Therapist Practice describes 5 components of patient management; examination, evaluation, diagnosis, prognosis, interventions and outcomes. Information collected during the examination is evaluated in an attempt to improve decision making regarding the most appropriate treatment strategy for the individual patient. Contrary to the medical model which attempts to identify pathology to arrive at a diagnosis, the diagnostic process in physical therapy involves classifying or labeling patients based on functional limitations (restrictions in activities caused by a certain condition) and impairments (loss or abnormality in function such as decreased strength or motion) in an attempt to specifically direct treatment. Clinical decision making regarding treatment involves a certain degree of uncertainty as to which interventions will maximize individual patient outcomes. While the amount of quality evidence supporting physical therapy interventions is increasing, this uncertainty can make it difficult to decide on an appropriate treatment strategy. The American Physical Therapy Association has stated that identifying subgroups of patients who are likely to benefit from specific treatments is a research priority. (APTA) The Guide to Physical Therapist Practice indicates that interventions such as mobilization/manipulation are utilized by physical therapists to manage patients who have shoulder pain. There is growing evidence that impairments in the cervicothoracic spine may contribute to shoulder pain, and that patients with shoulder pain may benefit from manipulation in this region. Manipulation is defined as a manual therapy technique comprising a continuum of skilled passive movements, including small-amplitude/high velocity movements (thrust) and oscillations (non-thrust), that is targeted at joints and soft tissues.

While it is not likely that all patients who have with shoulder pain will benefit from manipulation (thrust and non-thrust) of the cervicothoracic spine, it is possible that a subgroup exists that will experience rapid and dramatic improvement with the use of these manual physical therapy techniques. It is our specific aim to develop a clinical prediction rule (CPR) to identify patients with a primary complaint of shoulder pain who are likely to benefit from cervicothoracic manipulation. The purpose of a CPR is to improve the clinician's accuracy in predicting a diagnosis or an expected outcome. For example, CPRs exist to improve the accuracy of diagnosing ankle fractures in individuals with acute injuries,predict the likelihood of death within four years for individuals with coronary disease, or determine when cervical radiographs are required for patients who have experienced neck trauma. The process of developing and testing a CPR has been described in detail elsewhere. Although CPRs can be developed to improve the accuracy of making a certain diagnosis, the focus of this project is to develop a CPR to predict a certain treatment outcome. The development of a CPR utilizes diagnostic properties of sensitivity, specificity, and positive and negative likelihood ratios, which are based on the individual patient. Thus their interpretation can be readily applied to an individual patient. Development of a CPR to accurately predict which patients with shoulder pain will likely experience a clinically meaningful improvement in pain and function with cervicothoracic spine manipulation before treatment would be immensely helpful for clinicians in the decision-making process. Thus the purpose of this project is to develop a CPR to identify patients with shoulder pain likely to benefit from cervicothoracic spine thrust and non-thrust manipulation.