Evaluation of impairment related to low back pain.

Low back pain is the leading cause of disability and expense from work-related conditions in the United States. Forty percent of the expense of the worker's compensation program is spent on claims involving the low back. There are several systems of impairment evaluation in use in the United States, but the most commonly used has been developed by the American Medical Association. Evaluation of impairment related to the low back is expressed as a percent impairment of the whole person and is calculated by combining values related to: (1) diagnostic based categories, (2) range of motion of the spine, and (3) neurologic deficits in the lower extremities. Using this system, and given a cooperative patient, a reproducible quantification of impairment can be obtained to help administrators of the worker's compensation system more fairly compensate injured workers for partial permanent disability.