title: Pre-measurement rest time affects magnitude and reliability of toe pressure measurements.
abstract: OBJECTIVE
  Toe pressures are used to evaluate lower extremity healing capacity and screen for peripheral arterial disease (PAD). Although toe pressures are commonly used clinically both as an independent measure and in the calculation of the toe-brachial index, the effect of pre-measurement rest duration on the magnitude and reliability of toe pressures is unknown. This study investigated the effect of pre-measurement rest duration on toe pressures.
  
  
  METHODS
  Seventy community-based participants meeting guidelines for PAD screening were recruited. Systolic toe pressures either at the left or right hallux were manually measured using photoplethysmography following 5, 10 and 15 min of rest in a supine horizontal position. Testing was repeated 7-10 days later.
  
  
  RESULTS
  A significant drop in toe pressure (3.86 mmHg) occurred between 5 and 10 min (p = 0.001). No significant change occurred between 10 and 15 min. Reliability after 5 min was excellent (intra-class correlation coefficient, ICC = 0.80, 95% CI 0.68-0.89), increasing slightly at 10 and 15 min (ICC = 0.86, 95% CI 0.77-0.92 and ICC = 0.82, 95% CI 0.69-0.89).
  
  
  CONCLUSIONS
  Toe pressures stabilize after 10 min of rest in a supine horizontal position. Longer periods of pre-measurement rest did not improve reliability significantly.
authors.affiliation: School of Health Sciences, University of Newcastle , Ourimbah , Australia.
authors.forename: Vivienne Helaine
authors.initials: VH
authors.lastname: Chuter
authors.forename: Sarah Louise
authors.initials: SL
authors.lastname: Casey
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D055109:Ankle Brachial Index; D001794:Blood Pressure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000503:physiopathology*; D015203:Reproducibility of Results; D012146:Rest
keywords: Blood pressure; peripheral vascular disease; toe systolic pressure; toe–brachial index