Information on this page is drawn from "Prevention of vibration risks in the construction sector" published by European Agency for Safety and Health at Work
Whole-body Vibration
Whole-body vibration is caused by machines or vehicles that transmit vibration through the operator's feet, buttocks and back into his or her body. These include excavators, wheel loaders, caterpillars, graders, scrapers, site dumpers, articulated dump trucks, wheeled (motor) scrapers and fork-lift trucks used on uneven terrain.
Exposure to whole body vibration occurs when the body or parts of the body come in contact with a vibrating surface, such as the seat, pedal or floor of heavy vehicles or machinery. Whole body vibration exposure has been shown to be a strong contributor to lower back injuries. 1
Examples of exposure to whole body vibration 1
Operating backhoe
Operating skid-steer loader
The Potential Health Effects of Whole-body Vibration
Employees who are regularly exposed to whole-body vibration may suffer from lower back pain as well as disorders of the sensory functions or finemotor co-ordination. Factors such as twisting the body in constrained seated postures or exposing the spine to shocks or impact loads while using a vibrating machine place extra strain upon the spine.
The Distribution of Vibration-induced Disorders in Europe
Apart from mining, quarrying and manufacturing, construction is the sector in Europe most hit by occupational diseases. These include disorders that may be triggered by exposure to vibration. These are recognised as occupational diseases in many Member States of the European Union. A European Occupational Diseases Statistics (EODS) pilot study has shown that between 1995 and 2000 some 23% of 2,539 cases of disorders of the
locomotor apparatus of the hand and wrist, which are caused by mechanical vibration, occurred in the construction sector. By comparison, 28% were suffered by employees in manufacturing and 19% in mining.
Example: A building worker who has worked on construction sites since the age of 14, using drilling and pneumatic hammers three or four days a week for several hours, now suffers from an occupational disease. At the age of 42, the pain in his wrist is so severe that he can no longer work.
Example: A machine operator in Germany, who has driven an excavator and loader every day for some 20 years, has had to give up his job because the pain in his back is so severe. This situation could have been avoided if he had used a modern, well-designed and adjustable seat on his vehicle and limited his exposure; for example, by rotating jobs.
Reduction of Whole-body Vibration
When new machines are bought, models with appropriate performance should be selected. Preference should be given to machines with the lowest vibration emissions for a given performance.
The quality of roadway surfaces is an important factor in the reduction of vibration. Where possible on construction sites, uneven surfaces should be smoothed.
Suspension Seats
The machines should be equipped with suspension seats, which must be adjusted to the driver's weight, to reduce vibration to a minimum. This seat suspension system must be easily accessible and adjustable. Not every suspension seat is suitable for each and every machine. Information on suitable seats should therefore be obtained from the manufacturer before a seat is installed. A poor choice of seat may even increase vibration.
All seats are associated with a particular range of frequencies, which they amplify. Should the inherent frequencies of the vehicle lie within this range, the result is detrimental to the vibration exposure. Standards EN ISO 7096:2000, EN ISO 5007 and EN 13490:2001 contain vibration characteristics for earthmoving machines, agricultural tractors and industrial trucks.
References
1 Information in this section is drawn from "Participative ergonomics in civil construction handbook" published by Queensland Government
For More Information
The KARLA catalogue of representative noise and vibration data at the workplace (in German) may serve as an aid for estimating exposure to hand-arm and whole-body vibration. Further support for estimating exposure and calculators for hand-arm and whole-body vibration can be found at http://www.hse.gov.uk in English. Parameter calculators in German can be found on the BGIA's web pages at http://www.hvbg.de and at
http://www.bg-metall.de/index.php?id=180
