Earlier findings demonstrated that the comprehensive muscular activity profile (CMAP) system was a powerful clinical method for evaluating lumbar range of motion (ROM) and lifting capacity (LC) while also documenting participant effort. A subsequent study also reported the CMAP's clinical utility for patients with musculoskeletal pain claims. Building upon these studies, the present investigation evaluated the CMAP's ability to reliably differentiate between healthy individuals versus those with low back pain (LBP). Twenty LBP patients and 20 demographically matched healthy subjects were administered the CMAP protocol (measuring ROM and LC). For ROM, there were no significant differences between the groups for overall performance and for degree of effort. However, for the LC, there were significant differences between groups: the LBP patients displayed lower performance relative to normals. Results demonstrate the clinical utility of the CMAP for the objective quantification of functional differences between the two groups.