title: Effect of reclining a seat on the discomfort from vibration and shock on fast boats.
abstract: Passengers and crew on fast boats can experience high magnitudes of whole-body vibration and mechanical shocks that may present risks to health and cause discomfort. This study investigated the influence of reclining a seat on the discomfort caused by fast-boat motion and whether discomfort can be predicted by overall ride values according to current standards. Subjects judged the discomfort of simulations of a recorded fast boat motion in a seat reclined by 0°, 15°, 30°, 45°, or 60°. Reclining the seat caused no significant change in overall discomfort, suggesting that if a reclined seat can be shown to reduce risks of injury it may be acceptable in respect of comfort. The findings are inconsistent with the predictions of standards and show that revised frequency weightings are required to account for seat pan or seat back inclination.
  Contrary to predictions of current standards, reclining a seat may not increase discomfort during fast-boat motion. Revised frequency weightings for evaluating the severity of whole-body vibration are required to account for seat pan or seat back inclination.
authors.affiliation: a Human Factors Research Unit, Institute of Sound and Vibration Research, University of Southampton , Southampton , UK.
authors.forename: Henrietta V C
authors.initials: HV
authors.lastname: Howarth
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Griffin
mesh_terms: D000054:Acceleration / Q000009:adverse effects*; D000293:Adolescent; D000328:Adult; D004867:Equipment Design; D006804:Ergonomics / Q000379:methods*; D006260:Head Protective Devices; D006801:Humans; D008297:Male; D055595:Mechanical Phenomena; D008875:Middle Aged; D009038:Motion; D011187:Posture / Q000502:physiology*; D012767:Ships; D014732:Vibration / Q000009:adverse effects*; D055815:Young Adult
keywords: boats; discomfort; reclined seats; shock; whole-body vibration