Low back pain in the workman in Canada.

Groups of 25 Workmen's Compensation Board patients (WCP group) and 25 non-Workmen's Compensation Board patients (NWCP group) hospitalized because of low back pain were compared. The WCP group had a significantly higher male:female ratio, incidence of sudden onset and precipitating factors, and prevalence of weakness, decreased reflexes and sensory loss. Surgical treatment and multiple operations were significantly more frequent in the WCP group, as was complete long-term relief or worsening after operation. Adequate partial relief was significantly more frequent in the NWCP group. The differences suggest more severe conditions in the workmen. Prevalence of psychological factors was not significantly different, although a trend was observed for this to be greater in the WCP group.