title: Spinal height change in response to sustained and repetitive prone lumbar extension after a period of spinal unloading.
abstract: OBJECTIVE
  The purpose of this study was to investigate if differences in spinal height changes in healthy individuals were observed after a period of spinal unloading using repetitive as compared with sustained lumbar extension exercises.
  
  
  METHODS
  This study used a pretest, posttest, crossover design. Asymptomatic participants were recruited using convenience sampling. Thirty-two participants (15 male; 17 female) without back pain were included in the data analysis (mean, 24.4 years; range, 20-41 years). Participants performed sustained or repetitive prone lumbar extension exercises after 1 hour of sustained spinal unloading. Spinal height was measured using a stadiometer before and after the repetitive and sustained prone lumbar extension exercises.
  
  
  RESULTS
  Paired t tests revealed no significant difference in spine height after repetitive (P = .774) or sustained (P = .545) prone lumbar extension after a period of spinal unloading. No significant difference between spinal height changes occurred between sustained (mean [SD], -0.28 [2.59] mm) and repetitive (mean [SD], -0.12 [2.42] mm) lumbar extension (P = .756).
  
  
  CONCLUSIONS
  In this group of asymptomatic individuals, sustained and repetitive lumbar extension exercises did not appear to affect spinal height after a period of spinal unloading.
authors.affiliation: Research Associate, Center for Rehabilitation Research, Texas Tech University Health Sciences Center, Lubbock, TX.
authors.forename: M'Lyn
authors.initials: M
authors.lastname: Lazzarini
authors.affiliation: Professor, Center for Rehabilitation Research, Texas Tech University Health Sciences Center, Lubbock, TX. Electronic address: jm.brismee@ttuhsc.edu.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Brismée
authors.affiliation: Assistant Professor, Hampton University, Hampton, VA.
authors.forename: S Christopher
authors.initials: SC
authors.lastname: Owens
authors.affiliation: Associate Professor, Campbell University, Buies Creek, NC.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Dedrick
authors.affiliation: Professor, Center for Rehabilitation Research, Texas Tech University Health Sciences Center, Lubbock, TX.
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Sizer
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008161:Lumbosacral Region; D008297:Male; D016684:Prone Position; D013131:Spine / Q000033:anatomy & histology* / Q000502:physiology*; D016474:Weight-Bearing; D055815:Young Adult
keywords: Body Height; Intervertebral Disk; Prone Position; Spine