Many of our client’s drivers spend more and more time behind the wheel and, for many who work from their vehicle, the car is their office. Often clients who provide company cars to their employees have issues with those with bad backs and have to put additional policies in place to provide solutions to those drivers, so we thought we would explain how the ergonomics of cars should be setup as these are often overlooked when considering OHS in the office.
Firstly, car seating position is different from your office chair position as they are completely different activities – when driving, your arms are higher than they would be at your desk and you have to extend your legs further forward. On top of this, your body is subjected to vibrations, bumps, sideways movements and acceleration and deceleration when driving.
Driving injuries include foot cramps, low back pain, stiff neck, and sore shoulders from poor posture, stress, tension, and staying in one posture or position for an extended period of time and, in addition to proper ergonomics, it is important rest every 2 hours of continuous driving.
1. Seat height – raise the seat as high as you can but still be comfortable. This height will optimize your vision through the windows. You should be able to see at least 76 mm (3 in) over the top of the steering wheel. Ensure that you have sufficient room between the roof and the top of your head. Adjust the mirrors after you have finished setting the other features.
2. Seat cushion length – if possible adjust the seat length so that the back of your knees is about 3 – 6 cm (about 1-1/4 to 2-3/8 in) from the front on the seat.
3. Seat Forward/Back Position – move the seat forward until you can easily push the pedals through their full range with your whole foot, not just your toes. You may have to readjust the seat height to get better control of the pedals.
4. Seat Cushion Angle – tilt the seat cushion until your thighs are supported along the full length of the cushion without there being pressure at the back of your knees.
5. Seat Back Rest – adjust the back rest until it supports the full length of your back when you are stilling upright. If you are leaning too far back, you may end up bending your head and neck forward, which may cause muscle fatigue, neck or shoulder pain, tingling in the fingers, etc.
6. Lumbar Support – adjust the lumbar support up-and-down and in-and-out until you feel an even pressure along your back from the hips to shoulder height. As this point, the seat back should feel comfortable and there should be no gaps or pressure points in the back support area.
7. Steering wheel – adjust the steering wheel for height or tilt and pull it back for easy reach. The centre of the steering wheel should be about 25 – 30 cm (10 – 12 in) from the driver’s breast bone. The closer you are to the air bag, the higher the possibility of injury if the air bag deploys, even if you are wearing a seat belt.
If your steering wheel can be tilted up-and-down, tilt it so the air bag behind the centre of the steering wheel is pointing to your chest, not your head and neck or your stomach. In addition, your arms should be in a comfortable position (not too high or too low).
8. Head Restraint (head rest) – while sitting, raise the head restraint until the top of it is level with top of your head. If the head restraint can be tilted, adjust the angle of the head restraint until is practically touching the back of your head when you are in your sitting posture.
9. Fine Tuning – you may have to go through steps 1 – 8 again if you need to optimize the way that vehicle cab fits you. You should be able to reach and operate all of the controls, pedals, the steering wheel, etc., and have good visibility through the windows and mirrors.