Here are the numbers. 81% of British drivers suffer from foot cramps, 74% suffer from lumbar pain, 74% have a stiff neck, 74% have side aches, and 73% a headache/eye strain. 6.5% (2 million drivers) hurt after only 15 minutes of driving while 9% only need to drive 22 miles before symptoms start.
eBayMotors.co.uk went on to characterize the 4 most common driving postures and corrective actions for each. Here they are, and yes, this is what they called them.
The Rollercoaster
37% of drivers hold this position characterized by leaning forward and sitting upright, seat forward and arms and legs bent.
Corrected by relaxing and reclining the seat slightly to support the back.
The Multi-tasker
26% hold this position characterized by a straight back with arms bent and one hand on the gear shift.
Corrected by not multi-tasking. When driving just drive. Do not edit a report, eat or put on make-up. Reclining the seat slightly and placing both hand on the wheel help as well.
The Racer
19% hold this position characterized by straight arms and legs with a reclined seat and a low driving position.
Corrected by moving the seat so that arms and legs are slightly bent and raising the seat so that the hips are higher than the knees and the back is supported.
The Pimp
8% hold this position characterized by an inclined seat with one hand on the wheel and the other on the window ledge or hanging out the window entirely.
Corrected by growing up. Most Pimps were 25-35 year old men. It is also corrected by straightening the seat back so there is only a slight recline and raising the seat so the hips are above the knees. Rolling up the window to remind you to keep both hands on the wheel helps as well.
Automakers do a pretty good job now a day of providing a supportive seat. Of course the more adjustments the better. The point this study made was that you have to use them. Keep your hips above your knees, your upper and lower back supported and make sure your hands and feet can reach the wheel, gear shift and pedals without stretching.

