[Segmental functional disorders--a frequent cause of backache?].

Within a community survey the prevalence of lumbar and sacroiliac dysfunction was estimated in back pain sufferers from the general population. 3969 German residents aged 25 to 74 were randomly selected from a population registry. 3858 were contactable by mail, and 3109 (81%) responded to a postal screening questionnaire. Those 1263 persons (41%) who reported current or recent back pain were invited to a manual-diagnostic examination. The participation rate was 68%. In 1991 the three-step diagnostics according to Bischoff were performed for the operationalization of spinal dysfunction, while in 1992 the structural diagnosis following Greenman was used. Sex, age, current back pain, pain intensity and duration of the current back pain episode were assessed to determine their influence on prevalence. For three-step diagnostics the prevalence of lumbar and/or sacroiliac dysfunction was 19%, for structural diagnosis 22%. Females were significantly more often affected. Age showed no effect. Lumbar and/or sacroiliac dysfunction were significantly over-represented in people reporting current back pain. Nevertheless, the prevalence of silent dysfunction was about 10%. No association between pain intensity and lumbar and/or sacroiliac dysfunction was found. While lumbar dysfunction was linked with a short duration of the current back pain episode, sacroiliac dysfunction did not. Both diagnostic systems showed similar effects. The results suggest that the importance of spinal dysfunction in people with current back pain may have been overestimated. A classical case-control study is indicated for further analysis.