title: Rollator use does not consistently change the metabolic cost of walking in people with chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  To (1) evaluate whether the use of a rollator changed metabolic cost during a controlled walking task, and (2) explore relationships between the difference in dyspnea and metabolic cost associated with rollator use.
  
  
  METHODS
  Single-group interventional study in which patients completed 2 corridor walks: 1 without and 1 with a rollator, at the same individualized constant speed.
  
  
  METHODS
  Rehabilitation hospital.
  
  
  METHODS
  Patients with chronic obstructive pulmonary disease (N=15; 10 men; median age [interquartile range; IQR]=69 [12]y; forced expiratory volume in 1 second=42 [20]% predicted).
  
  
  METHODS
  Rollator use.
  
  
  METHODS
  Oxygen uptake, converted to metabolic equivalent units (METs), and minute ventilation were measured throughout both tasks using a portable gas analysis system; dyspnea and arterial oxygen saturation (SpO(2)) were collected on completion.
  
  
  RESULTS
  Median [IQR] walk speed [IQR] was 48 (10)m/min. Walking with a rollator, compared with walking without, reduced dyspnea (median [IQR]=1.0 [1.5] vs 2.0 [2.0]; P=.01) without changing energy expenditure (median [IQR]=2.8 [1.2] vs 3.2 [0.9] METs; P=.65), minute ventilation (median [IQR]=30.3 [9.6] vs 27.7 [9.9]L/min; P=.50), or SpO(2) (median [IQR]=92 [8]% vs 94 [10]%; P=.41). The association between the reduction in dyspnea and any difference in energy expenditure related to rollator use was of borderline significance (r(s)=.50; P=.06). Six of the 8 participants who experienced a reduction in dyspnea also demonstrated a reduction in the metabolic cost of walking.
  
  
  CONCLUSIONS
  The mechanism responsible for the amelioration in dyspnea during rollator-assisted walking is multifactorial. A reduction in the metabolic cost of walking may play a part in some, but not all, patients.
authors.affiliation: Department of Respiratory Medicine, West Park Healthcare Centre, Toronto, ON, Canada.
authors.forename: Kylie
authors.initials: K
authors.lastname: Hill
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Dolmage
authors.forename: Lynda J
authors.initials: LJ
authors.lastname: Woon
authors.forename: Dina
authors.initials: D
authors.lastname: Brooks
authors.forename: Roger S
authors.initials: RS
authors.lastname: Goldstein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004417:Dyspnea / Q000517:prevention & control / Q000534:rehabilitation; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000534:rehabilitation*; D011659:Pulmonary Gas Exchange; D012047:Rehabilitation Centers; D012129:Respiratory Function Tests; D012656:Self-Help Devices / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D014853:Walkers / Q000706:statistics & numerical data*; D016138:Walking / Q000502:physiology*