Direct observation of pain behavior in low back pain patients during physical examination.

Trained observers measured the occurrence of 5 behaviors (guarding, bracing, rubbing, grimacing, and sighing) in a group of 80 low back pain patients undergoing physical examination. Bracing was frequently displayed, rubbing, guarding, and grimacing were moderately frequent and sighing was infrequent. Pain behaviors were much more likely to occur when patients were moving than when they were in a static position. The rate of guarding, bracing, and total pain behavior was predicted by physical examination findings and/or number of prior operations. Patients having longer pain histories were also more likely to show guarded movement. Topics for future research in this area are identified, and the utility of behavioral observation for clinicians is discussed.