Reliability of joint mobility and pain assessment of the thoracic spine and rib cage in asymptomatic individuals.

Despite the importance of correctly diagnosing a spinal dysfunction, limited research exists related to physical therapists' ability to reliably identify a joint exhibiting signs of dysfunction. The purpose of this investigation was to determine the inter- and intra-examiner reliability of a thoracic spine and rib cage joint mobility and pain assessment between two experienced manipulative physical therapists. Nine healthy subjects (3 male, 6 female; ages 23-35) without history of mid- or low back pain participated. Posterior-to-anterior pressures were applied to the thoracic spine and rib articulations with anterior-to-posterior pressures applied to the costosternal joints of each subject by two examiners to evaluate joint mobility and pain provocation. Both examiners assessed all subjects twice and were blinded to subject identity. Kappa statistics were calculated using a strict and expanded definition of agreement to determine the between- and within-examiner reliability for each outcome. Intra-examiner reliability of joint mobility assessment ranged from slight to fair based on the strict agreement but improved to good when findings were compared across +/- 1 spinal/rib level. Pain provocation reliability increased to very good under the expanded agreement; however, this finding should be viewed with caution due to limited pain prevalence in the subject sample. Selected clinical prediction rules, applied to the care of individuals with back pain, characterize the patient's regional mobility simply as hypomobile, normal, or hypermobile; consequently, we feel the results of an expanded definition of agreement may be more appropriate for clinic practice. Further research is needed to determine the reliability in individuals with thoracic spine and rib cage symptoms.