// Driving

Driving and Ergonomics

Is sitting in a car seat the same as sitting in a chair? No, even though you are sitting, they are different activities.

Is sitting in a car seat the same as sitting in a chair?

context No, even though you are sitting, they are different activities. When you use the steering wheel, your hands and arms are higher than when you are working at a desk. To operate the brake and accelerator pedals, you have to extend your legs more forward than you would when sitting at a desk. One foot may be flat on the floor and the other at an angle to operate the accelerator and brake pedals. If your vehicle has a standard (manual) transmission, you must use the other foot on the clutch and one arm and hand to operate the gear shift.
context In addition, your body experiences up-and-down vibrations from the car travelling on uneven or bumpy road surfaces and the body moves sideways when you turn on corners. Depending on how fast you accelerate or decelerate, you will feel a force on your body.

Can driving cause discomfort or pain?

context Yes. Discomfort and lower back pain are frequent complaints reported by drivers. These 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. See the OSH Answers on musculoskeletal disorders for more information.

What occupations are at risk?

context Any person who spends a lot of time in a vehicle (car, truck, ambulance, etc.) is likely to experience aches and pains. Drivers tend to experience pain more often as it is more difficult to shift body positions while driving. However, passengers can also feel the same effects if they are sitting in a vehicle for prolonged periods without changing position or getting out of the vehicle and stretching or taking a break every hour or two where possible.

What causes these aches and pains?

Causes include:

context Poor posture - from personal habit, or from an improperly adjusted or fitted seat
context Low frequency whole-body vibration in moving cars and trucks can contribute to effects on the lower back
context The shape of the vehicle seat itself may put pressure on selected parts of the legs, back and buttocks. This contact can lead to pain or discomfort at pressure points and may affect blood flow to the legs and feet.

In general, what do I need to know to improve driving comfort?

To be comfortable while driving, look for features such as the interior of the vehicle designed to provide postural and thermal comfort, sufficient "room" or space, acceptable noise levels, and adjustable features that allow the driver to fit the vehicle to their needs. A vehicle's interior must be adjustable so drivers of different heights and shapes can: The driver should have sufficient room (25 - 30 cm or 10 - 12 in) between the steering wheel and his or her chest (breast bone) in order for the seat belt and air bag to provide the maximum safety protection in case of a crash. The steering wheel column should not interfere with leg movement or bump the knees when getting in and out of the vehicle or while steering and operating the pedals. You may also wish to make small adjustments to the seat from time to time if you are driving for long periods of time. Any position can become uncomfortable if maintained for a long period of time. As well, try to gently move your arms, legs, and neck if you are stopped at lights.

More specifically, what do I look for when selecting a vehicle?

Consider the following factors: If buying vehicles for a specific group of workers, ensure that they are able to provide input on the selection of vehicles. Examine various aspects of a vehicle, such as:

Getting in and out of the vehicle

Sitting in the cab

Seats

When properly adjusted, the driver should be able to reach the pedals, steering wheel and other controls without stretching the legs and arms and should have a good view of the instruments, gauges, and all mirrors, and a good vision through the front and side windows.

Seat Backrest and Lumbar Support

Seat Belt

Head Restraint (Headrest)

Although commonly called a headrest, it should be called a head restraint as it is designed to restrict head movement when a vehicle is hit from behind. The head restraint offers more protection when it is close to the head as the restraint will come in contact with the head faster and the contact lasts longer during a rear-end collision. A well-designed head restraint will decrease the likelihood of the neck bending backwards and causing whiplash.

Air Bags

The airbag is an additional occupant restraint device and should never be considered a substitute for a seat belt. A seat belt alone can protect drivers from injury in slow speed collisions, without the airbag deploying. The airbag is designed to deploy in cases of higher speed, frontal impact. If an airbag is deployed while the occupant is not wearing a seat belt, injuries are likely to occur. An airbag alone will not prevent an occupant from being ejected from the vehicle.

Steering Wheel

Pedals and Gear Shift

Trunk

Car Environment

How do I adjust the driver's seat to fit me?

Read the vehicle manual and understand all the adjustments that you can do (e.g., seat position, backrest angle, headrest position, steering wheel height and tilt, seat belt, mirrors). Common adjustments include: 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 of 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 sitting 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 breastbone. The closer you are to the airbag, the higher the possibility of injury if the airbag deploys, even if you are wearing a seat belt. If your steering wheel can be tilted up-and-down, tilt it so the airbag 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, steering wheel, etc., and have good visibility through the windows and mirrors.