title: A history of low back pain affects pelvis and trunk mechanics during a sustained lift/lower task.
abstract: This study compared three-dimensional trunk and pelvis range of motion (ROM) during a sustained asymmetric box lift/lower task between a group with a history of low back pain (HBP, n = 9) and a group with no history of low back pain (NBP, n = 9). Participants lifted an 11-kg box for 10 min at 12 cycles/min from ankle height in front to shelves 45 deg off-centre at waist height. Kinematic data were collected at the beginning (min1), middle (min5) and end of the bout (min9). Two-way analyses of variance were performed for all variables. Pelvis and trunk transverse ROM were similar at min1. By min9, HBP group did not change (31.9 ± 9 deg); however, ROM decreased in NBP group (21.6 ± 6 deg, p < 0.05). Therefore, despite no current pain, the HBP group demonstrated protective lifting mechanics compared to controls. Also discussed are implications for studying lifting paradigms at sub-maximal effort over longer periods of time.
  Differences between groups over time demonstrate residual consequences of low back pain (LBP) in a manual materials handling scenario. Individuals with a history of LBP (pain free for 6 months) demonstrated more conservative lifting mechanics towards the end of the bout compared to controls with no history of LBP.
authors.affiliation: Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA. joseph.seay@us.army.mil
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Seay
authors.forename: Shane G
authors.initials: SG
authors.lastname: Sauer
authors.forename: Peter N
authors.initials: PN
authors.lastname: Frykman
authors.forename: Tanja C
authors.initials: TC
authors.lastname: Roy
mesh_terms: D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D006801:Humans; D017770:Lifting; D017116:Low Back Pain / Q000503:physiopathology*; D008297:Male; D010384:Pelvic Bones / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology*; D060726:Torso / Q000502:physiology / Q000503:physiopathology*