title: Physical strain of walking relates to activity level in adults with cerebral palsy.
abstract: OBJECTIVE
  To gain insight into underlying mechanisms of inactive lifestyles among adults with spastic bilateral cerebral palsy (CP) with a focus on aerobic capacity, oxygen consumption, and physical strain during walking at preferred walking speed, as well as fatigue.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Adults (N=36), aged 25 to 45 years, with spastic bilateral CP, walking with (n=6) or without (n=30) walking aids.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Physical strain during walking was defined as oxygen uptake during walking, expressed as percentage of peak aerobic capacity. Participants with spastic bilateral CP walked their preferred walking speed while oxygen uptake was measured using a portable gas analyzer. Peak aerobic capacity was measured during maximal cycle ergometry. An accelerometry-based activity monitor measured total daily walking time. Regression analyses were performed to assess the relation between aerobic capacity, oxygen uptake, and physical strain of walking on the one hand and total daily walking time on the other hand.
  
  
  RESULTS
  Neither aerobic capacity nor oxygen uptake during walking was related to total daily walking time (r(2)=.29, P=.10 and r(2)=.27, P=.16, respectively). Physical strain of walking at preferred walking speed was inversely related to total daily walking time (r(2)=.44, P<.01).
  
  
  CONCLUSIONS
  Physical strain during walking is moderately related to total daily walking time, implying that people with high physical strain during walking at preferred walking speed likely walk less in daily life.
authors.affiliation: Department of Rehabilitation Medicine and Physical Therapy, Erasmus MC, University Medical Center, Rotterdam, The Netherlands. j.slaman@erasmusmc.nl
authors.forename: Jorrit
authors.initials: J
authors.lastname: Slaman
authors.forename: Johannes
authors.initials: J
authors.lastname: Bussmann
authors.forename: Wilma M
authors.initials: WM
authors.lastname: van der Slot
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Stam
authors.forename: Marij E
authors.initials: ME
authors.lastname: Roebroeck
authors.forename: Rita J
authors.initials: RJ
authors.lastname: van den Berg-Emons
mesh_terms: D061725:Accelerometry; D000328:Adult; D002547:Cerebral Palsy / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D017079:Exercise Tolerance; D005221:Fatigue / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D010101:Oxygen Consumption; D010809:Physical Fitness / Q000502:physiology*; D012044:Regression Analysis; D057185:Sedentary Behavior; D016138:Walking / Q000502:physiology*