title: Lower impulsive loadings following intensive weight loss after bariatric surgery in level and stair walking: a preliminary study.
abstract: BACKGROUND
  There are currently very few of studies which have evaluated the role of bariatric surgery in joint loadings and changes in gait. We wanted to examine how impulsive loading would change level and stair walking in severely or morbidly obese subjects after they had undergone bariatric surgery and weight loss.
  
  
  METHODS
  Thirteen female and three male adults aged between 30 and 63 years, cleared for Roux-en-Y gastric bypass, were recruited into this study. All subjects were severely or morbidly obese i.e., body mass index was >35 kg/m(2). The measurement methods consisted of triaxial skin mounted accelerometers and ground reaction force (GRF); conducted at two different predetermined gait speeds.
  
  
  RESULTS
  The average weight loss was 27.4 (SD8.7) kg after 8.8 (SD3.9) months of follow-up period. Most of the absolute GRF parameters decreased in proportion to weight loss. However, medio-lateral GRF parameters decreased more than expected. The general trend in the knee accelerations demonstrated lower impulsive loadings in both axial and horizontal directions after weight loss. We did not observe any significant changes in stair walking.
  
  
  CONCLUSIONS
  Weight loss after bariatric surgery not only induces a simple mass-related adaptation in gait but also achieves mechanical plasticity in gait strategy.
authors: Department of Applied Physics, University of Eastern Finland, Finland. Electronic address: timo.bragge@uef.fi.
authors: Timo
authors: T
authors: Bragge
authors: Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Finland; Palokka Health Center, Jyväskylä, Finland.
authors: Tarja
authors: T
authors: Lyytinen
authors: Department of Applied Physics, University of Eastern Finland, Finland.
authors: Marko
authors: M
authors: Hakkarainen
authors: Department of Applied Physics, University of Eastern Finland, Finland.
authors: Paavo
authors: P
authors: Vartiainen
authors: Muonio Health Center, Muonio, Finland.
authors: Tuomas
authors: T
authors: Liikavainio
authors: Department of Applied Physics, University of Eastern Finland, Finland.
authors: Pasi A
authors: PA
authors: Karjalainen
authors: Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Finland; Institute of Clinical Medicine, University of Eastern Finland, Finland.
authors: Jari P
authors: JP
authors: Arokoski
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D005260:Female; D005500:Follow-Up Studies; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000503:physiopathology / Q000601:surgery; D016138:Walking / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*
keywords: Accelerometer; Bariatric surgery; Biomechanics; Ground reaction force; Obesity