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Updated: May 11, 2026
09:35
Measurement of the Hand Transmitted Vibration of the Human Hand Arm System During Operation of a Hand Tractor
Published on: June 16, 2021
Determinants explaining the variability of hand-transmitted vibration emissions from two different work tasks:
Ingrid Liljelind1, Hans Pettersson, Leif Nilsson
1Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå university, SE-90187 Umeå, Sweden;
The Annals of Occupational Hygiene
|May 28, 2013
Summary
Machine brand and wheel wear significantly impact hand-transmitted vibration (HTV) exposure, explaining over 90% of variability. Operator characteristics had minimal influence on HTV exposure levels.
Area of Science:
- Occupational Health
- Ergonomics
- Vibration Engineering
Background:
- Hand-transmitted vibration (HTV) exposure is influenced by physical, biomechanical, and individual factors, leading to measurement variability.
- Understanding exposure variability and its determinants is crucial for improving workplace conditions.
- A quasi-experimental study was conducted to estimate variance components and evaluate determinant effects on HTV exposure.
Purpose of the Study:
- To identify and quantify the determinants of exposure variability in hand-transmitted vibration during routine work tasks.
- To evaluate the influence of machine type, wheel characteristics, task completion time, and operator factors on vibration exposure.
- To explain the sources of variability in hand-transmitted vibration measurements.
Main Methods:
- Eleven operators performed simulated tasks (weld puddle removal, steel pipe cutting) using four angle grinders (air and electric) and two brands of wheels.
- Vibration emission (a(sa)), wheel wear, and task completion time were recorded.
- Operator characteristics (age, hand dimensions, grip force, experience) were collected; statistical analysis used mixed and random effects models.
Main Results:
- Machine brand, wheel wear, and task completion time significantly affected vibration exposure (a(sa)), explaining over 90% of variability.
- Electrically powered machines showed 2.6 times higher a(sa) than air-driven machines.
- Operator factors contributed minimally (1%) to total variability, with hand volume, grip force, and body weight being significant for cutting, and grip force for grinding.
Conclusions:
- Determinants including machine brand, wheel brand, and task completion time explained over 90% of vibration exposure variability.
- Machine brand was the dominant determinant of vibration exposure.
- Operator variability was small, indicating a limited role in overall exposure.
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