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Whole body vibration

Whole-body vibration (WBV) is transmitted through the seat while driving
vehicles as part of their job e.g. dumper truck driver or feet and legs e.g.
aircraft cabin crew.
Frequent jolts and jarring can cause health risk including back pain.
The significant health effects include

• Back pain
• damage to soft tissues in the interverbal discs.
• Vertigo

Assessment of Vibration Exposure

A complete assessment of exposure to vibration requires the measurement of vibration
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acceleration in meters per second squared (m/s ). Vibration exposure direction is also important
and is measured in defined directions. Vibration frequencies and duration of exposure are also
determined. How hard a person grips a tool affects the amount of vibrational energy entering
the hands; therefore, hand-grip force is another important factor in the exposure assessment.

The amount of exposure is determined by measuring acceleration in the units of m/s .
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Acceleration is often used as a measure of vibration exposure for the following reasons:

• Several types of instruments are available for measuring acceleration, the rate of change of
velocity in speed or direction per unit time (e.g., per second).
• Measuring acceleration can also give information about velocity and amplitude of vibration.

• The degree of harm is related to the magnitude of acceleration.

Health research data tells us that the degree of harm is related to the magnitude of acceleration.

Vibration Exposure Standards

Exposure limit values and action values

For hand-arm vibration

• daily exposure limit value is 5 m/s2 A(8).
• daily exposure action value is 2.5 m/s2 A(8).
For whole body vibration

• daily exposure limit value is 1.15 m/s2 A(8).
• daily exposure action value is 0.5 m/s2 A(8).

ENSIGN | Unit IG2 – Element 5 – Physical and Psychological 13
Health