In this study, dealing with the early diagnosis and prevention of back pains, adolescent postural faults especially in the sagittal plane were examined with a standardized physical examination technique suitable for use in schools; the strength and flexibility of muscles affecting the back were investigated; neck and/or back symptoms were screened; and the association of background factors and the findings of the physical examination with symptoms was evaluated. The material consisted of a total of 370 11, 13, 15 and 17-year-old comprehensive and senior secondary school pupils from a small suburban municipality, selected by random sampling. The subjects were quite evenly distributed in terms of different age and sex groups. The physical examination of the back, with evaluation of symptoms, took place in the autumn of 1981 in the premises of school health care, and 58 of the examined subjects were referred on the basis of symptoms and/or findings to an X-ray examination of the thoracic and/or lumbar spine. The X-rays were taken in the spring of 1982. 1 Back pain history. Relation between present neck and/or back symptoms, background variables and findings in physical examination. 7.6% of the subjects reported previous neck and/or back symptoms that had interfered with their school work or leisure activities. Present, mainly mild neck and/or back symptoms were reported by 19.7%. Girls reported symptoms more often than boys (p less than 0.05), and the occurrence of symptoms increased with age (p less than 0.001). Roughly one third of the subjects had frequent symptoms. Pains were most often localized in the low back (p less than 0.001) and were most frequently associated with sitting or physical activities. Most subjects who had suffered from previous symptoms also reported symptoms at the time of the study. These more chronically symptomatic subjects accounted for 6.2% of the total material. 2.9% of siblings under 11 years, 8.0% of siblings 11-17 years, and 13.7% of siblings over 17 years of age had at some time prior to the study complained of recurrent neck and/or back symptoms. Of mothers, 19.0% and of fathers, 15.4% reported neck and/or back symptoms that were continual and/or reduced working ability. The mother (p less than 0.01) and/or the father (p less than 0.05) of a subject reporting frequent symptoms, also reported neck and/or back symptoms.(ABSTRACT TRUNCATED AT 400 WORDS)