Centralization of low back pain and perceived functional outcome.

McKenzie's methods for evaluating and treating low back pain are used often but studied little. When using the McKenzie system, it is important to observe signs of symptom movement to a central location (centralization). This study investigated the relationships between centralization of low back pain and/or radiculopathy and the subjects' rating of functional outcome. Thirty-six subjects with low back pain volunteered to participate and were evaluated and treated by six researchers. Subjects were tested initially and again 14 days after initiation of treatment using the Oswestry Low Back Pain Disability Questionnaire and the Performance Assessment and Capacity Testing Spinal Function Sort (SFS). Symptoms were monitored for the occurrence of "complete centralization." Of the 36 subjects, 25 showed complete centralization within 14 days. The SFS score changes were significantly higher for subjects who completely centralized (p = 0.015). The results supported the hypothesis that subjects who centralize will have improved functional outcome and, thus, quality of life. However, shorter time to occurrence of complete centralization does not necessarily correlate with improved outcome.

Perceptions of smoking risk as a function of smoking status.

Perceptions of the health risks associated with smoking in comparison with not smoking were assessed for the self and the "typical smoker" among four groups of adults: current, former and nonsmokers in the community, and smokers who had joined cessation clinics to help them quit. Comparisons across groups indicated that risk perceptions differed as a function of smoking status. Clinic attendees reported the highest smoking risk and the greatest perceived benefit of not smoking, and community smokers reported the lowest of each. In addition, community smokers were the only group to exhibit an "optimistic bias" (i.e., a perception that they were less vulnerable to health risk than was the typical smoker). Results from this cross-sectional study suggest that the decision to engage in and to stop risky behaviors is related to the perceptions of the health risk associated with those behaviors.