Ever wondered or analysed why your back aches in the car but in no other seat? Perhaps you’re just doing a lot of kilometres but maybe there’s more to the story. I’m regularly asked to conduct vehicle ergonomic assessments to determine fit and suitability for a worker reporting back pain or neck pain.
Driving is indeed associated with physical risk factors including sustained sitting and sometimes awkward postures. Underlying these physical risk exposures may be industrial issues, psychosocial factors and personal preferences which can motivate workers to raise concerns about particular work vehicles. This multifactorial problem can create significant challenges for safety and health professionals when trying to assess risk, manage injury and provide solutions.
By contrast, establishing the presence or absence of vehicle-related physical risk factors such as poor ergonomics, is a relatively simple and objective process compared with the complexity of addressing psychosocial risk factors. Some of the common problems encountered include:
- Single cab utes often don’t offer sufficient rear space to recline the back rest. An average or taller driver will require the seat at its most rear position to accommodate their legs, leaving no space to recline the back rest. In contrast to many of the ergonomic images seen, people are not comfortable sitting upright at 90°. In fact, research shows lowest spinal loading exists at 100-110°. Let’s clarify – its less at 180°! – but if you’re driving then a slight recline is best. There’s no need to bring your protractor in to work; Most people will intuitively recognise the comfort of a slight recline.
- Tall and heavy workers, mainly men, are poorly accommodated in small cars. The Hyundai i30 wagon is a popular fleet option for sales staff and the like, however this vehicle and others in its class, can impose incredibly awkward postures – knees pressed against the dash and head hitting the roof!
- Sedan seating in general offers a lower hip position (hips closer to the floor well) compared with SUV-style seating. When the knees are positioned above the hips, as might be the case for a tall male in a small car or ute, this puts the hamstrings on stretch and in turn, increases low back loading.
These are just a few of the most common physical risk factors which may be implicated in driver reports of back pain. Consider also exposure to Whole Body Vibration (WBV), addressed in our previous post, and driving duration.
For workers reporting musculoskeletal discomfort from their vehicle, consider an ergonomic assessment. When the physical risk factors are well managed, employers can rest assured they are doing all they can to support a worker. Any further intervention can then be directed toward treatment of personal and/or psychosocial factors.