[Risk factors for low back pain among 1.389 pupils in the 8th and 9th grade. An epidemiologic study]. / Risikofaktorer for laendesmerter hos 1.389 skoleelever i 8.- og 9.-klasse. Et epidemiologisk studie.

INTRODUCTION: The aim of this study was to investigate the frequency and severity of low back pain (LBP) in 13-16-year-old pupils in relation to selected factors, such as anthropometry, physical activity, smoking, hypermobility, and tightness of hamstring muscles. METHODS: The study was designed as a cross-sectional questionnaire-based survey and all the pupils were examined by the school doctor for height, weight, mobility of joints, and general health status. RESULTS: The lifetime prevalence of non-specific LBP was 58.9% and the one-year prevalence was 50.8% with no differences between the sexes. Recurrent/continuous LBP in a moderate to severe degree was recorded in 19.4% of the school children (182 F, 88 M). This was positively correlated to a female gender, a BMI of more than 25 kg/square meter, competitive sports for boys, poor physical fitness, daily smoking, heavy jobs in leisure time, increased use of the health system, and reduced life quality. DISCUSSION: Stepwise logistic regression analysis indicates that a female gender, daily smoking, and heavy jobs are important associated factors for severe LBP in adolescents, with an observed probability of 46% if all factors are present. We do not know yet whether these factors have any causal importance for the development of severe LBP.