title: A radiostereometric analysis of the movements of the sacroiliac joints in the reciprocal straddle position.
abstract: METHODS
  A Radiostereometric analysis of the reciprocal straddle position.
  
  
  OBJECTIVE
  To evaluate the magnitude of rotation in the sacroiliac joints in the reciprocal straddle position.
  
  
  BACKGROUND
  The reciprocal straddle position has been objectified in different studies, using different techniques, to show a sacroiliac motion between 5 degrees and 36 degrees. Previous studies with radiostereometric analysis during different provocations reported much smaller movements.
  
  
  METHODS
  Six women with posterior pelvic pain of long duration after pregnancy (n = 5) and sacroiliitis (n = 1) underwent radiostereometric analysis in the sustained reciprocal straddle position.
  
  
  RESULTS
  A reciprocal movement could be demonstrated in the sacroiliac joints in the reciprocal straddle position. However, the movements were 10 times smaller than reported in earlier studies of the reciprocal straddle position.
  
  
  CONCLUSIONS
  It was possible to demonstrate reciprocal movements of the sacroiliac joints in the straddle position. However, the radiostereometric analysis technique showed the movements to be small, as reported in other mobility studies.
authors.affiliation: Department of Orthopaedics NVS Angelholm, Sweden. bengt.sturesson@angelholm.mail.telia.com
authors.forename: B
authors.initials: B
authors.lastname: Sturesson
authors.forename: A
authors.initials: A
authors.lastname: Uden
authors.forename: A
authors.initials: A
authors.lastname: Vleeming
mesh_terms: D000328:Adult; D018771:Arthralgia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D017699:Pelvic Pain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011187:Posture / Q000502:physiology*; D011859:Radiography; D012399:Rotation; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology