title: Biomechanic evaluation of the Rola Stretcher as a passive distraction device.
abstract: BACKGROUND
  Many devices have been marketed claiming to increase the mobility of the articulations of the spine with active or passive distraction. In this study, the Rola Stretcher (Unique Relief, Inc, Davenport, Iowa) and an earlier version, the True Back II (True Back, Inc, Clearwater, Fla), were evaluated to see if they have a measurable biomechanic effect on the spine.
  
  
  METHODS
  Two studies were conducted, each with 6 male participants and 6 female participants, using a stadiometer to accurately measure a person's sitting height. The increase in sitting height after using the True Back II or Rola Stretcher for 10 minutes was compared with that after lying supine for 10 minutes. A third intervention, a firm foam block cut to the same size and shape as the True Back II, was also used in this study.
  
  
  RESULTS
  The Rola Stretcher had a significantly greater lengthening effect on the spine compared with supine rest (P <0050). The True Back II had a similar but lesser effect (P <.0509). Women demonstrated a greater height gain than men.
  
  
  CONCLUSIONS
  The True Back II and the Rola Stretcher in particular appear to lengthen the spine after a single use of 10 minutes. The observed discrepancy between the effects in men and women may be an experimental artifact occurring as a result of less effective resetting of the posturing mechanisms in men compared with women. A trend showed the Rola Stretcher to be more effective than the foam block.
authors.affiliation: Palmer Center for Chiropractic Research, Palmer College of Chiropractic, Davenport, IA 52242, USA. jdevocht@engineering.uiowa.edu
authors.forename: J W
authors.initials: JW
authors.lastname: Devocht
authors.forename: M H
authors.initials: MH
authors.lastname: Pope
authors.forename: M
authors.initials: M
authors.lastname: Magnusson
authors.forename: K F
authors.initials: KF
authors.lastname: Spratt
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D006801:Humans; D008297:Male; D020393:Manipulation, Spinal / Q000295:instrumentation*; D008875:Middle Aged; D015915:Motion Therapy, Continuous Passive / Q000295:instrumentation*; D011336:Probability; D012016:Reference Values; D013122:Spinal Diseases / Q000534:rehabilitation*; D016896:Treatment Outcome