title: Energetics and mechanics of walking in patients with chronic low back pain and healthy matched controls.
abstract: OBJECTIVE
  Walking in patients with chronic low back pain (cLBP) is characterized by motor control adaptations as a protective strategy against further injury or pain. The purpose of this study was to compare the preferred walking speed, the biomechanical and the energetic parameters of walking at different speeds between patients with cLBP and healthy men individually matched for age, body mass and height.
  
  
  METHODS
  Energy cost of walking was assessed with a breath-by-breath gas analyser; mechanical and spatiotemporal parameters of walking were computed using two inertial sensors equipped with a triaxial accelerometer and gyroscope and compared in 13 men with cLBP and 13 control men (CTR) during treadmill walking at standard (0.83, 1.11, 1.38, 1.67 m s(-1)) and preferred (PWS) speeds. Low back pain intensity (visual analogue scale, cLBP only) and perceived exertion (Borg scale) were assessed at each walking speed.
  
  
  RESULTS
  PWS was slower in cLBP [1.17 (SD = 0.13) m s(-1)] than in CTR group [1.33 (SD = 0.11) m s(-1); P = 0.002]. No significant difference was observed between groups in mechanical work (P ≥ 0.44), spatiotemporal parameters (P ≥ 0.16) and energy cost of walking (P ≥ 0.36). At the end of the treadmill protocol, perceived exertion was significantly higher in cLBP [11.7 (SD = 2.4)] than in CTR group [9.9 (SD = 1.1); P = 0.01]. Pain intensity did not significantly increase over time (P = 0.21).
  
  
  CONCLUSIONS
  These results do not support the hypothesis of a less efficient walking pattern in patients with cLBP and imply that high walking speeds are well tolerated by patients with moderately disabling cLBP.
authors.affiliation: Service of Rheumatology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Yves
authors.initials: Y
authors.lastname: Henchoz
authors.affiliation: Institute of Sport Sciences of the University of Lausanne (UNIL-ISSUL), Bâtiment Géopolis, 1015, Lausanne, Switzerland.
authors.forename: Nicola
authors.initials: N
authors.lastname: Soldini
authors.affiliation: University of La Réunion, UFR SHE, CURAPS-DIMPS, Le Tampon, La Réunion, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Peyrot
authors.affiliation: Institute of Sport Sciences of the University of Lausanne (UNIL-ISSUL), Bâtiment Géopolis, 1015, Lausanne, Switzerland. davide.malatesta@unil.ch.|Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland. davide.malatesta@unil.ch.
authors.forename: Davide
authors.initials: D
authors.lastname: Malatesta
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D059350:Chronic Pain / Q000503:physiopathology*; D005080:Exercise Test; D005684:Gait / Q000502:physiology*; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D016138:Walking / Q000502:physiology*
keywords: Biomechanics; Gait; Human locomotion; Inverted pendulum; Pain