A statistical comparison of biomechanical back performance measures for physician-referred back patients versus normals

The purpose of this research was to develop descriptive measures of back performance and use these to develop a classification model for discriminating between patients and normals. This model could then be adapted to a pre-employment screening tool and a performance monitoring tool. Pre-employment screening could prevent persons with the back pathology of an injured person from being placed in jobs which place high stresses on the back. A biomechanical model was used which provides an objective means for obtaining quantitative measures. Five tests were performed: range of motion, isometric, rotational, flexion/extension, and lateral flexion. Six variables were collected using these tests: range of motion, torque, velocity, impulse, work, and power. Normality and means tests were run on the variables. Factor analyses were run on the variables and eight factors with significant variables were identified. The highest loading variable from each factor was then analyzed with a discriminant analysis and a classification and regression trees analysis. Both of these classification procedures yielded a model which could be used for a pre-employment screening test and a performance monitoring tool.