title: Slump sitting X-ray of the lumbar spine is superior to the conventional flexion view in assessing lumbar spine instability.
abstract: Flexion radiographs have been used to identify cases of spinal instability. However, current methods are not standardized and are not sufficiently sensitive or specific to identify instability.
  
  
  
  This study aimed to introduce a new slump sitting method for performing lumbar spine flexion radiographs and comparison of the angular range of motions (ROMs) and displacements between the conventional method and this new method.
  
  
  
  This study used is a prospective study on radiological evaluation of the lumbar spine flexion ROMs and displacements using dynamic radiographs.
  
  
  
  Sixty patients were recruited from a single spine tertiary center.
  
  
  
  Angular and displacement measurements of lumbar spine flexion were carried out.
  
  
  
  Participants were randomly allocated into two groups: those who did the new method first, followed by the conventional method versus those who did the conventional method first, followed by the new method. A comparison of the angular and displacement measurements of lumbar spine flexion between the conventional method and the new method was performed and tested for superiority and non-inferiority.
  
  
  
  The measurements of global lumbar angular ROM were, on average, 17.3° larger (p<.0001) using the new slump sitting method compared with the conventional method. They were most significant at the levels of L3-L4, L4-L5, and L5-S1 (p<.0001, p<.0001 and p=.001, respectively). There was no significant difference between both methods when measuring lumbar displacements (p=.814).
  
  
  
  The new method of slump sitting dynamic radiograph was shown to be superior to the conventional method in measuring the angular ROM and non-inferior to the conventional method in the measurement of displacement.
authors.affiliation: University Orthopaedics, Hand and Reconstructive Microsurgery (UOHC), National University Health System, 1E Kent Ridge Rd, NUHS Tower Block Level 11, Singapore 119228, Singapore. Electronic address: dennis_hey@nuhs.edu.sg.
authors.forename: Hwee Weng Dennis
authors.initials: HW
authors.lastname: Hey
authors.affiliation: University Orthopaedics, Hand and Reconstructive Microsurgery (UOHC), National University Health System, 1E Kent Ridge Rd, NUHS Tower Block Level 11, Singapore 119228, Singapore.
authors.forename: Eugene Tze-Chun
authors.initials: ET
authors.lastname: Lau
authors.affiliation: University Orthopaedics, Hand and Reconstructive Microsurgery (UOHC), National University Health System, 1E Kent Ridge Rd, NUHS Tower Block Level 11, Singapore 119228, Singapore.
authors.forename: Joel-Louis
authors.initials: JL
authors.lastname: Lim
authors.affiliation: Department of Diagnostic Imaging, National University Health System, 1E Kent Ridge Rd, NUHS Tower Block Level 12, Singapore 119228, Singapore.
authors.forename: Denise Ai-Wen
authors.initials: DA
authors.lastname: Choong
authors.affiliation: Saw Swee Hock School of Public Health, Tahir Foundation Building, National University of Singapore, 12 Science Drive 2, #10-01, Singapore 117549, Singapore.
authors.forename: Chuen-Seng
authors.initials: CS
authors.lastname: Tan
authors.affiliation: University Orthopaedics, Hand and Reconstructive Microsurgery (UOHC), National University Health System, 1E Kent Ridge Rd, NUHS Tower Block Level 11, Singapore 119228, Singapore.
authors.forename: Gabriel Ka-Po
authors.initials: GK
authors.lastname: Liu
authors.affiliation: University Orthopaedics, Hand and Reconstructive Microsurgery (UOHC), National University Health System, 1E Kent Ridge Rd, NUHS Tower Block Level 11, Singapore 119228, Singapore.
authors.forename: Hee-Kit
authors.initials: HK
authors.lastname: Wong
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011187:Posture; D011446:Prospective Studies; D016059:Range of Motion, Articular
keywords: Dynamic; Flexion; Instability; Lumbar; Slump sitting; X-rays