title: Evaluation of load carriage systems used by active duty police officers: Relative effects on walking patterns and perceived comfort.
abstract: OBJECTIVE
  This study aimed to examine the effects of two different load carriage systems on gait kinematics, temporospatial gait parameters and self-reported comfort in Swedish police.
  
  
  METHODS
  21 active duty police officers were recruited for this crossover study design. Biomechanical and self-report data was collected on two testing occasions. On occasion 1, three dimensional kinematic data was collected while police wore a/no equipment (control), b/their standard issues belt and ballistic protection vest and c/a load bearing vest with ballistic protection vest. Police then wore the load bearing vest for a minimum of 3 months before the second testing occasion.
  
  
  RESULTS
  The load bearing vest was associated with a significant reduction in range of motion of the trunk, pelvis and hip joints. Biomechanical changes associated with the load bearing vest appeared to reduce with increased wear time. In both the standard issue belt condition and the load bearing vest condition, police walked with the arms held in a significantly greater degree of abduction. Self-report data indicated a preference for the load bearing vest.
  
  
  CONCLUSIONS
  The two load carriage designs tested in this study were found to significantly alter gait kinematics. The load bearing vest design was associated with the greatest number of kinematic compensations however these reduced over time as police became more accustomed to the design. Results from this study do not support selection of one load carriage design over the other and providing individuals with the option to choose a load carriage design is considered appropriate.
authors.affiliation: School of Health Sciences, Jönköping University, Sweden. Electronic address: Nerrolyn.ramstrand@ju.se.
authors.forename: Nerrolyn
authors.initials: N
authors.lastname: Ramstrand
authors.affiliation: Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University, Göteborg, Sweden.
authors.forename: Roland
authors.initials: R
authors.lastname: Zügner
authors.affiliation: School of Health Sciences, Jönköping University, Sweden.
authors.forename: Louise Bæk
authors.initials: LB
authors.lastname: Larsen
authors.affiliation: School of Health Sciences, Jönköping University, Sweden; Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University, Göteborg, Sweden.
authors.forename: Roy
authors.initials: R
authors.lastname: Tranberg
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003258:Consumer Behavior; D018592:Cross-Over Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000502:physiology; D016495:Police; D011481:Protective Clothing; D016059:Range of Motion, Articular; D057566:Self Report; D060726:Torso / Q000502:physiology; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing
keywords: Biomechanics; Equipment; Ergonomics; Kinematics; Law enforcement; Load bearing vest; Musculoskeletal disorders; Temporospatial