title: Acute Cardiorespiratory and Metabolic Responses During Exoskeleton-Assisted Walking Overground Among Persons with Chronic Spinal Cord Injury.
abstract: BACKGROUND
  Lower extremity robotic exoskeleton technology is being developed with the promise of affording people with spinal cord injury (SCI) the opportunity to stand and walk. The mobility benefits of exoskeleton-assisted walking can be realized immediately, however the cardiorespiratory and metabolic benefits of this technology have not been thoroughly investigated.
  
  
  OBJECTIVE
  The purpose of this pilot study was to evaluate the acute cardiorespiratory and metabolic responses associated with exoskeleton-assisted walking overground and to determine the degree to which these responses change at differing walking speeds.
  
  
  METHODS
  Five subjects (4 male, 1 female) with chronic SCI (AIS A) volunteered for the study. Expired gases were collected during maximal graded exercise testing and two, 6-minute bouts of exoskeleton-assisted walking overground. Outcome measures included peak oxygen consumption (V̇O2peak), average oxygen consumption (V̇O2avg), peak heart rate (HRpeak), walking economy, metabolic equivalent of tasks for SCI (METssci), walk speed, and walk distance.
  
  
  RESULTS
  Significant differences were observed between walk-1 and walk-2 for walk speed, total walk distance, V̇O2avg, and METssci. Exoskeleton-assisted walking resulted in %V̇O2peak range of 51.5% to 63.2%. The metabolic cost of exoskeleton-assisted walking ranged from 3.5 to 4.3 METssci.
  
  
  CONCLUSIONS
  Persons with motor-complete SCI may be limited in their capacity to perform physical exercise to the extent needed to improve health and fitness. Based on preliminary data, cardiorespiratory and metabolic demands of exoskeleton-assisted walking are consistent with activities performed at a moderate intensity.
authors.affiliation: Beyond Therapy, Shepherd Center, Atlanta, Georgia.|Hulse Spinal Cord Injury Laboratory, Shepherd Center, Atlanta, Georgia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Evans
authors.affiliation: Virginia C. Crawford Research Institute, Shepherd Center, Atlanta, Georgia.
authors.forename: Clare
authors.initials: C
authors.lastname: Hartigan
authors.affiliation: Virginia C. Crawford Research Institute, Shepherd Center, Atlanta, Georgia.
authors.forename: Casey
authors.initials: C
authors.lastname: Kandilakis
authors.affiliation: Beyond Therapy, Shepherd Center, Atlanta, Georgia.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Pharo
authors.affiliation: Virginia C. Crawford Research Institute, Shepherd Center, Atlanta, Georgia.
authors.forename: Ismari
authors.initials: I
authors.lastname: Clesson
mesh_terms: D000328:Adult; D002908:Chronic Disease; D004734:Energy Metabolism / Q000502:physiology*; D000067190:Exoskeleton Device; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology; D010865:Pilot Projects; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D016138:Walking / Q000502:physiology
keywords: cardiovascular physiology; energy metabolism; exercise therapy; oxygen consumption; physical fitness; spinal cord injuries; walking