Sit with your body all the way back in your seat.
your back should be pressed against the backrest,and your bottom should be as far back in your seat as possible.Avoid driving scorched farward: if you cann't reach the pedals or steering wheel,adjust your seat, not your body.
Correct Sitting Posture:
When stationary, you should be able to sit with your shoulder blades pressed back into the chair and, with a straight arm, your wrist should be able to bend over the edge of the steering wheel. Then, when driving, you should find that you have a bend in your arm of around 120 degrees: 120o.
TIPS
1. Support Your Back
Slide your tailbone as close to the seat back as possible. Aim for a two- to three-finger gap between the back of your knees and the front of your seat. If your vehicle doesn’t allow for the proper position, a lumbar or back cushion may help.
2. Lift Your Hips
If you can, adjust your “seat pan” (the part you sit on) so that your thighs are supported along their entire length and your knees are slightly lower than your hips. This will increase circulation to your back while opening up your hips.
3. Don’t Sit Too Close
You should be able to comfortably reach the pedals and press them through their full range with your entire foot. Safety is also a consideration here; this study suggested that drivers whose chests were closer to the wheel were significantly more likely to suffer severe injuries to the head, neck and chest in front- and rear-end collisions.
4. Get The Right Height
Make sure your seat raises your eye level at least three inches above the steering wheel while allowing sufficient clearance between your head and the roof.
5. Lean Back (A Little)
The angle of your seat back should be a little greater than a perpendicular 90 degrees. At 100 to 110 degrees, the seat will put the least pressure on your back. Leaning too far back forces you to push your head and neck forward, which can cause neck and shoulder pain and tingling in the fingers.
6. Set Your Headrest
Set the top of the headrest between the top of your ears and the top of your head; it should just touch the back of your head when you’re sitting comfortably. The headrest is also important in reducing whiplash injuries in the event of a rear-end collision, says NHTSA—so important, in fact, that standards were developed for it.
7. Use Lumbar Support
If your car has adjustable lumbar support, set it (using both the front-back and up-down controls) so you feel an even pressure from your hips to your shoulders. If your car doesn’t have automatic support, a lumbar pillow or even a rolled-up towel can help.
8. Adjust Your Mirrors
Prevent neck strain by making sure your rear-view and side mirrors are properly adjusted; you should be able to see the traffic behind you without having to crane your neck.
9. Take Breaks
Even when you’re perfectly situated in the driver’s seat, fatigue will inevitably set in, especially when you’re driving for long periods. Listen to your body. And take periodic breaks: Park safely at a rest stop or other designated stopping area to get out of the car and stretch.
