A quasi-static discomfort measure in whole-body vibration.
A new methodology for objective evaluation of discomfort in whole-body vibration (WBV) is introduced in this work. The proposed objective discomfort characterizes discomfort based on the relative motion between adjacent segments of the human body from neutral positions. It peaks when the joints reach their limits. The objective discomfort has been tested on five subjects in the fore-aft direction using discrete sinusoidal frequencies of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 12, 14, and 16 Hz. Each frequency file runs for 15 s with a 3 s resting period as a reference for discomfort comparison. All files run at a constant acceleration of 0.7 m/s(2). The subjects were tested with back support and without back support, and their subjective discomfort was reported based on the Borg CR-10 scale. The proposed objective discomfort has shown significant correlation with the subjective discomfort. The objective discomfort has also been tested on five subjects under multiple-axis random WBV with three common industrial seating configurations (seat-mounted control, floor-mounted control, and steering wheel), and has shown promising results.
Rahmatalla
Salam
S
Department of Civil and Environmental Engineering, 4121 Seamans Center for Engineering, The University of Iowa, Iowa City, Iowa 52242, USA. salam-rahmatalla@uiowa.edu
Smith
Rosalind
R
Meusch
John
J
Xia
Ting
T
Marler
Tim
T
Contratto
Michael
M
D000328:Adult; D001334:Automobile Driving; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D016273:Occupational Exposure / Q000009:adverse effects / Q000517:prevention & control / Q000706:statistics & numerical data; D010147:Pain Measurement / Q000379:methods*; D011187:Posture; D011482:Protective Devices; D014732:Vibration / Q000009:adverse effects*; D055815:Young Adult