title: Toe blood pressure and leg muscle oxygenation with body posture.
abstract: BACKGROUND
  In 1980 Katkov and Chestukhin measured blood pressures and oxygenation invasively at various body tilt angles at different locations on the body, including the foot. To our knowledge, such measurements have not been performed noninvasively. Therefore, the purpose of this study was to measure toe blood pressure (TBP) and lower limb muscle oxygenation noninvasively at various body tilt angles, and to assess the use of a Finometer for noninvasive TBP measurements. Our noninvasive results are compared with those performed by Katkov and Chestukhin. We hypothesized that: 1) the Finometer provides a noninvasive measurement of TBP at different tilt angles; and 2) muscle oxygenation is highest with 0 and -6 degrees, and decreases with increased head-up tilt (HUT).
  
  
  METHODS
  There were 10 subjects who were exposed to different body tilt angles (-6, 0, 10, 30, 70, and 90 degrees). At each angle we measured TBP noninvasively with a Finometer and muscle tissue oxygenation by near infrared spectroscopy.
  
  
  RESULTS
  We found a strong correlation between TBP using the Finometer and TBP predicted by adding the hydrostatic component due to body tilt to the standard arm blood pressure measurement. At 10, 30, 70, and 90 degrees both TBP and tissue oxygenation were significantly different from the 0 degree (supine) level. Oxygenation decreased and TBP increased with higher HUT angles. No differences were observed in TBP or oxygenation between -6 and 0 degree.
  
  
  CONCLUSIONS
  The Finometer accurately measures TBP noninvasively with body tilt. Also, muscle oxygenation is highest at small HUT angles and decreases with increased HUT.
authors: Department of Orthopaedic Surgery, University of California, San Diego, CA, USA. rosalesarmando@gmail.com
authors: Armando
authors: A
authors: Rosales-Velderrain
authors: Michael
authors: M
authors: Cardno
authors: Jaime
authors: J
authors: Mateus
authors: Ravindra
authors: R
authors: Kumar
authors: Thomas
authors: T
authors: Schlabs
authors: Alan R
authors: AR
authors: Hargens