ABSORPTION OF ENERGY DURING WHOLE-BODY VIBRATION EXPOSURE

✍ Scribed by R. Lundström; P. Holmlund

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 264 KB
• Volume: 215
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1998.1594

✦ Synopsis

Absorbed power, PAbs , during exposure to vertical and horizontal whole-body vibration in sitting posture was measured using 15 male and 15 female subjects. Different experimental conditions were applied, such as vibration level (0•25-1•4 m/s 2 ), frequency (1•13-80 Hz), body weight (54-93 kg), relaxed and erect upper body posture. Results show that PAbs was strongly related to frequency of the vibration peaking, within the range of 4-6 Hz and below 2•5 Hz for vertical and horizontal directions respectively. PAbs increased with acceleration level and body weight. If risk assessment is based on the assumption that the amount of PAbs , independence of the frequency of the vibration, indicates a hazard, then the frequency weighting procedure in ISO-standard 2631 can be questioned. The ISO weighting for horizontal vibration seems to underestimate the risk for frequencies within the range of about 1•5-3 Hz and overestimate them above about 5 Hz. For the vertical direction the frequency weighting overestimates the risk for frequencies above about 6 Hz. The results also indicate a need for differential guidelines for females and males. Many types of vehicle produce whole-body vibration with frequencies in the range where the highest PAbs was observed.

Although not yet thoroughly evaluated, PAbs may be a better quantity for risk assessment than acceleration as specified in ISO 2631, since it also takes into account the dynamic force applied to the human body.