[Pelvic floor relaxation--a condition with many names and uncertain criteria].
Pain in the pelvis and lower back appears to be becoming an increasing problem in Norway. The relation between pelvic pain and low back pain is unclear. In the literature a variety of designations, such as pelvic girdle relaxation, pelvic joint instability, posterior pelvic pain, peripartum pelvic pain etc. have been used as identifying labels. The condition(s?) seems to be culturally specific for the Nordic countries in particular. However, pelvic pain is also recognized in England, Holland and Australia, but seemingly unknown in France, Germany, Italy and Spain. The article describes the current knowledge--focusing criteria, etiology, prevalence and nomenclature--and points to the need for systematic epidemiological and clinical investigations.