Revised protocol for the kinematic assessment of impairment.

BACKGROUND CONTEXT Marras et al. developed a functional motion performance tool that accurately identified impaired low back motion performance, with sensitivity of 90% and specificity of 94%. However, the protocol required testing of five controlled tasks and was relatively time consuming. PURPOSE To determine whether a more time-efficient low back motion functional performance evaluation tool with acceptably high sensitivity and specificity could be developed. STUDY DESIGN/SETTING Low back functional motion (kinematic) performance evaluations were completed on two groups, consisting of controls (no history of back pain) and low back pain patients. A second low back pain population was also evaluated prospectively to assess recovery. PATIENT SAMPLE The study population consisted of 335 patients and 374 controls. Thirty acute low back pain patients were monitored prospectively. OUTCOME MEASURES Kinematic low back functional performance measures. METHODS Low back motion functional performance was measured using the lumbar motion monitor. A revised discriminant function model was developed using data from only one of the five original functional motion performance control tasks. Prospective study data were used to track differences in recovery time between the revised and original discriminant function models. RESULTS The revised model using functional motion performance from the controlled sagittally symmetric task had a sensitivity of 90% and specificity of 92%. When comparing the revised and original model results, the time to recovery was the same in 90% of cases. CONCLUSIONS The revised (more time efficient) testing procedure yielded high sensitivity and specificity.