Whole-body Vibration and Ergonomics of Driving Occupations

Stina Eneman News

Proven studies conclude that the Whole Body Vibration workers can endure during a working shift can be a major contribution to Sickness and Work related illnesses.

What’s surprising is that it is not a condition isolated to vehicles working for example in a mining or off road application such as Forestry and Quarry work. Vibrations can come in all applications, a forklift working on a rough yard, the “stop start” journey of a commuter train and even a bus on a route with potholes and speedhumps.

Back disorders are the most common form of ill health at work and costs the UK economy estimated £7bn a year. The exact cause of back pain is often unclear but back pain is more common in jobs that involve driving, especially over long shift patterns, distances or machinery operating on rough ground.

Driving exposes the vehicle’s occupants to whole-body vibration that may include the shocks and jolts that are believed to increase the likelihood of injury or pain in the lower back. It is estimated that 9.0 million workers are exposed to Whole Body Vibration each week and a staggering 383,000 workers are exposed to magnitudes greater than 15 VDV.

The Control of Vibration at Work Regulations 2005 was introduced by the HSE set guidelines concerning the daily exposure to vibration where the vibration magnitude (root-mean-square frequency-weighted acceleration magnitude) in one of the three orthogonal directions, x, y and z, at the supporting surface

The exposure to vibration is averaged over a week and is the total exposure occurring within a period of seven consecutive days, normalised to a duration of five 8-hour days (40 hours).

During a working shift driving a bus, coach, construction machine or truck, the human back goes through every extremity, not only from the driving position but from the vehicles vibrations either from the terrain the vehicle is working on or simple “jolts” created on the road from potholes. Even a bus driver taking fares can go through many twists and turns throughout their working day as they greet passengers or navigate bus stops through heavy traffic checking mirrors.

The key to reducing Whole Body Vibrations is to understand the application the seat is being used in, it can mean vehicle, road surface, driver weight and shift pattern. We do this using our Vibindictor devices.

Pads fitted on the seat, the device will then record the X, Y and Z over a shift and report back the levels the drivers are subjected to.

Sometimes the solution can be as simple as changing the drivers break times so that the Maximum exposure limits are avoided, other solutions can mean changing routes, repairing yard surfaces and changing the seat.

Another Common Misconception is a really soft spongy seat is the best option for maximum comfort levels, whilst this is true for the first hour of sitting, very quickly the occupant finds this uncomfortable and the body starts to move in the seat trying to gain a suitable posture.

In order to maintain a low level of VDV the seat must be firm with good support and be fitted with various adjustment controls on the seat to change the vibration direction on the human body throughout the working day. A seat with a good level of control function and adjustability can signifcantly reduce WBV.

Back in 1949, its something Be-Ge’s founder realised when he introduced to the market the World’s first suspended driver’s seat and fitted our seats in Scania trucks. In context the rest of the truck market at that time were using basic non suspension seats and even wooden benches in some vehicles.

Our Be-Ge driver seat designs are based on the knowledge that different applications require different seats. The vibrations produced by construction vehicles or the small dimensions in forklifts require completely different seat designs than those in trucks and buses.

We understand that the most important feature on any seat is to be able to make personal adjustments to suit the stature, weight, and working environment for the driver. The key to any suspension seat is to be adjustable to the drivers weight, if we take for instance a 75kg driver on a maximum suspension setting, their weight would have very little effect on the suspension unit and they might as well be sat on a static seat. We offer weight independent height adjustment of 100mm, so the resistance on the suspension unit can be adjusted to suit the drivers weight.

To meet every need, we develop our Be-Ge products in close collaboration, both with users and vehicle manufacturers and enlist the expertise of ergonomic and medical experts as well as specialist researchers. For instance our patented Rotolift unit with foot pedestal enables a bus driver to rotate their seat in the direction of fare paying passengers so they can take the fares forward facing and greet the passengers “eye to eye” on the bus without the need to twist their body.

Once they have completed the fares another press on the foot pedal allows them to turn the seat towards driving direction.

That’s why when you buy a Be-Ge seat from us, we look closely at the application and its working environment, to come up with a drivers seat that is not only comfortable for the occupant, but will offer the maximum levels of safety and occupational health risks.

Gary Shaw – Be-Ge Seating UK Ltd