Whole body vibration
Whole body vibration (WBV) is vibration transferred to the human body through a supported surface or through the feet.
Drivers, operators or passengers in vehicles and machines travelling over uneven or unsealed surfaces might experience WBV. Standing on a platform attached to concrete crushing plant might also cause exposure.
WBV includes sharp impacts like shocks and jolts. These impacts can increase your risk of developing health problems.
How WBV affects workers
If you are frequently exposed to high levels of WBV, you could experience musculoskeletal disorders of the lower back, neck, and shoulders. While the most commonly reported health effect is lower back pain, you can also experience:
- neck and shoulder problems from damage to bones, joints, ligaments and tendons
- sciatic (back and leg) pain
- herniated discs
- early degeneration of the spine.
Exposure to WBV can also lead to:
- cardiovascular, respiratory, endocrine, and metabolic changes
- digestive problems
- reproductive damage in females
- impaired vision.
The general discomfort and fatigue can also lead to other workplace injuries.
Contributing factors
Factors that can increase WBV exposure include:
- heavy, repetitive, physical work
- frequent bending and twisting of the trunk
- forceful movement such as lifting
- static work postures
- repetitive work
- increased speed of movement
- cold work temperatures.
How WBV is measured
WBV must be measured by a competent person at the point where vibration enters the body, for example at the plant operator’s seat.
The standards for measuring WBV are:
- AS 2670.1-2001: Evaluation of human exposure to whole-body vibration, Part 1: General requirements, and
- EN 14253:2003: Mechanical vibration – Measurement and calculation of occupational exposure to whole-body vibration with reference to health - Practical guidance.
Vibration emissions data from plant manufacturers can also be used to work out the vibration likely to enter a worker’s body when operating their equipment.
Workplace exposure standards
There are currently no legislated workplace exposure standards established for WBV. A comparison of vibration magnitude can be made using an acceptable standard to determine a worker’s risk to WBV exposure.
The exposure action and limit values outlined within the European Union (EU) 2002/44/EC Physical Agents Directive is one such standard that can be applied to assess workers daily exposure, A(8). The directive offers the following exposure values for WBV:
- Exposure Action Value (EAV) – if the daily vibration exposure is likely to exceed an A(8) of 0.5m/s2 or a Vibration Dose Value (VDV) of 9.1m/s1.75 action should be taken to reduce exposure to below this value.
- Exposure Limit Value (ELV) – controls must be implemented to ensure workers are not exposed to a daily vibration exposure A(8) of more than 1.15m/s2 or VDV of 21m/s1.75.
What employers must do
Section 19 of the Work Health and Safety (WHS) Act 2011 states that a person conducting a business or undertaking (PCBU) has a primary duty to ensure, so far as is reasonably practicable, that worker exposure to WBV is eliminated. Where elimination is not reasonably practicable, the PCBU must minimise the risk so far as is reasonably practicable.
Clause 60 of the WHS Regulation 2017 states that a PCBU must manage risks to health and safety relating to a musculoskeletal disorder associated with a hazardous manual task, including tasks that expose workers to WBV.
The PCBU therefore has an obligation to identify work processes that expose workers to WBV and ensure appropriate control measures are implemented, managed, and reviewed to eliminate the risk of WBV exposure. Where it is not reasonably practicable to eliminate the risk, the PCBU must minimise the risk of workers developing health effects caused by WBV, so far as is reasonably practicable.
In managing risks to health and safety, the PCBU should check the:
- level of vibration
- workers’ frequency and duration of exposure
- design and layout of plant and vehicles.
Control measures
These controls should be considered by a PCBU to control worker exposure to WBV:
- Substitution – apply alternative work methods to reduce vibration exposure, for example transport materials by conveyor rather than mobile plant.
- Task/process design – improve road surfaces, minimise travel distances, reduce vehicle speeds and relocate machine controls to minimise repeated stretching.
- Purchasing policy – buy low vibration. Ensure a policy is in place that considers vibration emissions, ergonomic factors, driver vision and other operational requirements.
- Equipment selection – choose suitable equipment to ensure tasks are completed efficiently. Select cabin layouts where the operator can maintain a comfortable, upright position without having to twist excessively, or maintain a twisted posture for long periods.
- Suspension seats – choose seat suspension so the seat doesn’t hit its top or bottom end stops to prevent shock vibration and back injury.
- Maintenance – regularly service, maintain and repair plant, vehicles and roadways to help reduce vibration magnitudes and shocks. This could include maintaining tyres and replacing defective bearings.
- Information, training, and instruction – provide workers and supervisors with information on:
- health effects linked to prolonged exposure to WBV
- how to detect and report the signs/symptoms of WBV injury
- control measures used to control exposure to WBV
- the results of any WBV risk assessments and WBV measurements
- how to report plant/vehicles that need maintenance.
- Work schedules – implement work/rest cycles where practicable to allow workers to alternate work tasks to limit vibration exposure.
Health monitoring
There is no legal requirement under the WHS Regulation 2017 for PCBUs to provide health monitoring of workers exposed to WBV, however PCBUs should make sure employees experiencing symptoms of WBV see a doctor experienced in health monitoring.