title: Non-specific low back pain in adolescents from the south of Portugal: prevalence and associated factors.
abstract: BACKGROUND
  Low back pain (LBP) is a common condition in children and adolescents, and the prevalence has been increasing over the years. Most cases of LBP are due to non-specific causes; however, the role of these risk factors is still controversial. This study determined the prevalence of LBP in Portuguese adolescents and characterized the associated factors.
  
  
  METHODS
  The design of this study was observational, analytical and cross-sectional. The sample included 966 adolescents from southern Portugal, aged between 10 and 16 years. The assessments included a questionnaire to characterize the presence of LBP, postural habits, body mass index (BMI) and backpack weights and to use a scoliometer to evaluate the presence of scoliosis.
  
  
  RESULTS
  One hundred fifty-two (15.7 %) students had LPB at the present time, 456 (47.2 %) had experienced it in the last year, and 600 (62.1 %) had lifetime prevalence of LBP. Girls have 2.05 more probability of presenting LBP than boys (95 % CI 1.58-2.65; p < 0.001), and older students have a 1.54 greater probability (95 % CI 1.19-1.99; p = 0.001). Students who sit with the spine incorrectly positioned presented 2.49 greater probability of having LBP (95 % CI 1.91-3.2; p < 0.001), students using improper positions for watching TV or playing games have 2.01 greater probabilities (95 % CI 1.55-2.61; p < 0.001), and those who adopt an incorrect standing posture have a 3.39 greater chance of experiencing LBP (95 % CI 2.19-5.23; p < 0.001).
  
  
  CONCLUSIONS
  This study found a high prevalence of LBP in adolescents, with higher values in older students, female students and those who adopted incorrect positions when sitting or standing.
authors.affiliation: School of Health Jean Piaget Algarve, Piaget Institute, Enxerim, Silves, 8300-025, Portugal, beatriz.minghelli@silves.ipiaget.pt.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Minghelli
authors.forename: Raul
authors.initials: R
authors.lastname: Oliveira
authors.forename: Carla
authors.initials: C
authors.lastname: Nunes
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D011174:Portugal / Q000453:epidemiology; D011187:Posture; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012600:Scoliosis / Q000150:complications*; D011795:Surveys and Questionnaires