title: A technique to record the sedentary to walk movement during free living mobility: A comparison of healthy and stroke populations.
abstract: Hesitation between moving from a sedentary posture (lying/sitting) to walking is a characteristic of mobility impaired individuals, as identified from laboratory studies. Knowing the extent to which this hesitation occurs during everyday life would benefit rehabilitation research. This study aimed to quantify this transition hesitation through a novel approach to analysing data from a physical activity monitor based on a tri-axial accelerometer and compare results from two populations; stroke patients and age-matched unimpaired controls.
  
  
  
  Stroke patients living at home with early supported discharge (n=34, 68.9YO±11.8) and age-matched controls (n=30, 66.8YO±10.5) wore a physical activity monitor for 48h. The outputs from the monitor were then used to determine the transitions from sedentary to walking. The time delay between a sedentary posture ending and the start of walking classified four transition types: 1) fluent (<=2s), 2) hesitant (>2s<=10s), 3) separated (>10s) and 4) a change from sedentary with no registered walking to a return to sedentary.
  
  
  
  Control participants initiated walking after a sedentary posture on 92% of occasions. Most commonly (43%) this was a fluent transition. In contrast stroke patients walked after changing from a sedentary posture on 68% of occasions with only 9% of transitions classed as fluent, (p<0.05).
  
  
  
  A new data analysis technique reports the frequency of walking following a change in sedentary position in stroke patients and healthy controls and characterises this transition according to the time delay before walking. This technique creates opportunities to explore everyday mobility in greater depth.
authors.affiliation: Biomedical Engineering, University of Strathclyde, UK. Electronic address: a.kerr@strath.ac.uk.
authors.forename: Andy
authors.initials: A
authors.lastname: Kerr
authors.affiliation: Institute for Applied Health Research, Glasgow Caledonian University, UK.
authors.lastname: Rafferty
authors.affiliation: School of Health Sciences, University of Salford, UK.
authors.lastname: Hollands
authors.affiliation: Stroke MCN, NHS Lanarkshire, UK.
authors.lastname: Barber
authors.affiliation: School of Health Sciences, University of Salford, UK.
authors.lastname: Granat
mesh_terms: D061725:Accelerometry; D000368:Aged; D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic; D009068:Movement; D011187:Posture; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D016138:Walking
keywords: Free-living mobility; Physical activity monitor; Sedentary to walk; Stroke