title: Oral contraceptive use among female elite athletes and age-matched controls and its relation to low back pain.
abstract: BACKGROUND
  Exogenous and endogenous female sex steroids may influence the risk of low back pain. The fact that back pain is a very common symptom during pregnancy supports this theory. Back pain is also more common among female than male athletes. Oral contraceptives have been suggested to increase the risk of low back pain.
  
  
  OBJECTIVE
  To evaluate whether the prevalence of low back pain is higher among oral contraceptive users than non-users and if it differs between women taking part in different sports.
  
  
  METHODS
  A questionnaire was sent to female elite athletes in volleyball (n = 205), basketball (n = 150), and soccer (n = 361) as well as to age-matched controls (n = 113). The questionnaire comprised questions about age, constitution, occupation, parity and use of contraceptive method as well as previous and current back pain and possible consequences of the back problems.
  
  
  RESULTS
  The response rate was 85%. Between 42% and 52% of the women in the different groups used oral contraceptives. The groups were similar in most background variables, except that the volleyball and basketball players were taller. The prevalence of current low back pain was between 21% and 34% in the different athlete groups with an average of 30%, whereas only 18% of the controls suffered from low back pain (p < 0.01). The prevalence of low back pain within each group, athletes as well as controls, was similar in women who used, and did not use oral contraceptives.
  
  
  CONCLUSIONS
  This study does not support the theory that low back pain is affected by the use of oral contraceptives. Instead, constitutional factors and mechanical stress during intense physical activity is probably more important.
authors.affiliation: Department of Obstetrics & Gynaecology, Faculty of Health Sciences, University Hospital, Linköping, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Brynhildsen
authors.forename: H
authors.initials: H
authors.lastname: Lennartsson
authors.forename: M
authors.initials: M
authors.lastname: Klemetz
authors.forename: P
authors.initials: P
authors.lastname: Dahlquist
authors.forename: B
authors.initials: B
authors.lastname: Hedin
authors.forename: M
authors.initials: M
authors.lastname: Hammar
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000188:drug therapy / Q000209:etiology*; D001490:Basketball; D003276:Contraceptives, Oral / Q000009:adverse effects*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000139:chemically induced*; D008297:Male; D011247:Pregnancy; D012307:Risk Factors; D012737:Sex Factors; D012916:Soccer; D013177:Sports; D011795:Surveys and Questionnaires; D013548:Sweden
chemical_list: D003276:Contraceptives, Oral