Nonorganic signs of significance in low back pain

Medical records and imaging studies including one or more interviews and physical examinations by the author were reviewed in 878 people remaining out of work for 13 weeks or more because of occupational low back pain.

To assess the prognostic value of nonorganic signs, including those validated by Waddell et al and two others previously undescribed, limitation of shoulder motion with production of low back pain, and low back pain resulting from movement limited to the cervical spines.

Review of all records of people evaluated by the author over a 3-year period (1990-1993) provided the material for this study. All available medical, insurance, and legal records were reviewed, including reports or examination results of radiographic films, or both. In the majority, more sophisticated investigation had been performed with complete reports of the studies themselves being available to the author.

A complete history and physical examination were accomplished by the author on each individual, including evaluation of each of the test results for nonorganicity. Medical records, including radiographic films, magnetic resonance imaging, computerized axial tomography, myelography, bone scan, electromyography, etc., were collated. Statistical analysis of results followed.

The finding of limitation of shoulder motion resulting in low back pain indicated a worse prognosis for return to work than that of positive Waddell signs alone, 69.6% versus 52.9%. If cervical motion additionally produced low back pain, the outlook was poorer (no return to work in 73.1%).

When present with a triad of the signs validated by Waddell, the new signs significantly increase the predictability of failure to return to work by workers with compensable low back pain.