title: Reduction in finger blood flow induced by hand-transmitted vibration: effect of hand elevation.
abstract: OBJECTIVE
  This study investigated the effect of hand elevation on reductions in finger blood flow (FBF) induced by hand-transmitted vibration.
  
  
  METHODS
  Fourteen males attended six sessions on six separate days, with a control sessions and a vibration session (125-Hz vibration at 44 ms(-2) rms) with the right hand supported at each of three elevations: 20 cm below heart level (HL), at HL, and 20 cm above HL. Finger blood flow on the left and right hand was measured every 30 s during each 25-min session comprised of five periods: (1) no force and no vibration (5 min), (2) 2-N force and no vibration (5 min), (3) 2-N force and vibration (5 min), (4) 2-N force and no vibration (5 min), and (5) no force and no vibration (5 min).
  
  
  RESULTS
  Without vibration, FBF decreased with increasing elevation of the hand. During vibration of the right hand, FBF reduced on both hands. With elevation of the right hand, the percentage reduction in FBF due to vibration (relative to FBF on the same finger at the same elevation before exposure to vibration) was similar on the middle and little fingers of both hands. After cessation of vibration, there was delayed return of FBF with all three hand heights.
  
  
  CONCLUSIONS
  Vibration of one hand reduces FBF on both exposed and unexposed hands, with the reduction dependent on the elevation of the hand. The mechanisms responsible for vibration-induced reductions in FBF seem to reduce blood flow as a percentage of the blood flow without vibration. Tasks requiring the elevation of the hands will be associated with lower FBF, and the FBF will be reduced further if there is exposure to hand-transmitted vibration.
authors: Human Factors Research Unit, Institute of Sound and Vibration Research, University of Southampton, Southampton, SO17 1BJ, UK.
authors: Ying
authors: Y
authors: Ye
authors: Clinical Unit of Occupational Medicine, Department of Medical Sciences, Trieste General Hospitals, University of Trieste, 34129, Trieste, Italy.
authors: Marcella
authors: M
authors: Mauro
authors: Clinical Unit of Occupational Medicine, Department of Medical Sciences, Trieste General Hospitals, University of Trieste, 34129, Trieste, Italy.
authors: Massimo
authors: M
authors: Bovenzi
authors: Human Factors Research Unit, Institute of Sound and Vibration Research, University of Southampton, Southampton, SO17 1BJ, UK. M.J.Griffin@soton.ac.uk.
authors: Michael J
authors: MJ
authors: Griffin
mesh_terms: D000328:Adult; D005385:Fingers / Q000098:blood supply*; D006225:Hand / Q000098:blood supply; D053421:Hand-Arm Vibration Syndrome / Q000503:physiopathology; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D012039:Regional Blood Flow / Q000502:physiology; D014732:Vibration / Q000009:adverse effects*; D055815:Young Adult
keywords: Finger blood flow; Hand elevation; Hand-arm vibration syndrome; Hand-transmitted vibration; Vibration-induced white finger