A method to quantify hand-transmitted vibration exposure based on the biodynamic stress concept

Area of Science:

• Occupational Health and Safety
• Biomechanics
• Ergonomics

Background:

• Vibration-induced disorders are a significant occupational health concern.
• Current methods for assessing vibration risk, like ISO weighting, may not fully capture biodynamic stress in different hand-arm system substructures.

Purpose of the Study:

• To develop a practical method for quantifying biodynamic stress-cycle measures.
• To compare this new measure with existing ISO-weighted and unweighted accelerations.
• To assess the application potential of the biodynamic stress-cycle measure in predicting hand-arm vibration disorders.

Main Methods:

• A mechanical-equivalent model of the hand-arm system was created using experimental data.
• Average stresses in the fingers and palm were estimated using the model.
• Frequency weightings of stresses were derived using the proposed biodynamic stress-cycle measure.

Main Results:

• The frequency dependence of average stress in the fingers differs from that in the palm.
• This suggests that the frequency dependencies of finger disorders may differ from those affecting the palm, wrist, and arms.
• The biodynamic stress in fingers may be more critical for vibration-induced white finger (VWF) than stress in other substructures.

Conclusions:

• The proposed biodynamic stress-cycle measure offers a more nuanced understanding of vibration exposure.
• ISO weighting may underestimate high-frequency effects relevant to finger disorders.
• The biodynamic stress-cycle measure shows potential for improved risk assessment of hand-arm vibration disorders.