Distinguishable groups of musculoskeletal low back pain patients and asymptomatic control subjects based on physical measures of the NIOSH low back atlas

The authors performed an empirical prospective study of 115 patients referred to physical therapy for low back pain and 112 control subjects of similar age and gender. The authors defined and compared subgroups based on physical tests and described demographic and psychosocial characteristics by group. Prospective studies of intervention for persons with low back pain are limited by inability to randomize subjects into distinguishable groups. Previous attempts have not been empirical and have not focused on musculoskeletal LBP. Ten physical therapists administered 52 tests and 6 questionnaires to subjects in seven different clinics. Data were subjected to reliability and cluster and comparative analyses. Tests were reliable. Groups were distinguished by measures of symmetry, flexibility, strength, and dynamic mobility. Distinguishable groups can be determined; decreased trunk mobility characterized all groups of patients and imbalances in muscle length, strength, and symmetry described specific groups of subjects with and without low back pain.