Open AccessThe effects of Posture on seat-to-head Whole-Body Vibration Transmission
Author(s) -
Robert J. Jack,
Tammy Eger
Publication year - 2008
Publication title -
journal of low frequency noise, vibration and active control
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 25
eISSN - 2048-4046
pISSN - 1461-3484
DOI - 10.1260/026309208786926831
Subject(s) - whole body vibration , accelerometer , vibration , trunk , head (geology) , structural engineering , sitting , acceleration , transmissibility (structural dynamics) , acoustics , orthodontics , medicine , engineering , physics , vibration isolation , geology , ecology , quantum mechanics , geomorphology , classical mechanics , biology , pathology
Five male subjects were exposed to root-mean-square whole-body vibration (WBV) acceleration levels ranging from 0.011m/s 2 to 0.615m/s 2 while seated on a vibration simulator. During the WBV exposure, subjects adopted 5 unsupported trunk flexion/extension positions (15, 10, 0, −10 and −15, ±2.5 degrees from vertical), and 4 hip flexion positions (−10, 0, 10, and 20 degrees from the horizontal). WBV measurements were taken with a tri-axial accelerometer at the buttock/seat interface and the head. Hydrostatic weighing was also conducted to determine the subject's adipose content. Adipose content of the individual had no significant relationship with the seat-to-head transmission of vibration. Vibration exposures at 4Hz had significantly more transmission than vibration exposures at 6.3Hz. Vibration exposures in the Z-axis (vertical) had significantly more vibration transmission than vibration exposures in the X- (front-to-back) and Y-axes (left-to-right). A significant interaction was also found between trunk position, frequency and axis of exposure.