title: Changes in posture and perceived exertion in adolescents wearing backpacks with and without abdominal supports.
abstract: OBJECTIVE
  The goal was to examine whether backpacks with an abdominal support device improve posture and decrease exertion while walking among adolescents.
  
  
  METHODS
  Double-blinded trial, with 20 subjects, performed at a University Spine Center. On day 1, adolescents walked on a treadmill for 5 mins with photographic measurement of posture and responded to the Borg scale of perceived exertion before and after ambulation. On day 2, they repeated the trial four more times wearing a backpack randomly loaded with either 10% or 20% of body weight and with or without the Back Balancer abdominal support. Postural measures were recorded by a blinded observer.
  
  
  RESULTS
  Postural changes (forward lean) wearing a backpack with abdominal support were significantly lower while carrying both 10% and 20% of body weight (P = 0.024 and P = 0.008, respectively) vs. no abdominal support. In addition, perceived exertion at 10% and 20% of body weight was significantly greater without abdominal support (P = 0.042 and P = 0.018, respectively).
  
  
  CONCLUSIONS
  Forward lean and perceived exertion while wearing backpacks in adolescents can be significantly decreased with abdominal support. This may increase comfort and decrease complications, such as back pain, that may arise from backpack use.
authors.affiliation: Physical Medicine and Rehabilitation, Spine Program, The University of Michigan, 325 East Eisenhower Parkway, Ann Arbor, MI 48108, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Marsh
authors.forename: Lisa
authors.initials: L
authors.lastname: DiPonio
authors.forename: Karen
authors.initials: K
authors.lastname: Yamakawa
authors.forename: Seema
authors.initials: S
authors.lastname: Khurana
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Haig
mesh_terms: D000005:Abdomen; D000293:Adolescent; D001415:Back / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009989:Orthotic Devices; D005082:Physical Exertion / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011482:Protective Devices; D016138:Walking / Q000502:physiology; D014892:Weight Perception / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology