Driver's back pain and its prevention. A review of the postural, vibratory and muscular factors, together with the problem of transmitted road-shock.

There is evidence that those who spend more than half their working lives driving are three times more likely to suffer back trouble than the rest of the population. The causes have not been clearly defined. Sitting is a source of postural, spinal stress which can be disabling for those who have had serious back and sciatic pain. The muscular exertion of driving also adds to spinal stress. In many commercial vehicles, the driver is subjected to vibration at the natural frequency of the human trunk: and the resulting 'vibrocreep' may contribute further to the pattern of spinal stress. In addition, the transmission of road-shocks increases the muscular effort of driving as well as loading the spine. The capacity of the spine to resist such jerks is not fully understood, but it is believed that the mechanical 'conditioning' of the spine increases its susceptibility to minor injury which, if repeated, leads to an early onset of degeneration. The solution is to design a seat to support the back in a posture which minimises spinal stress, and to isolate the seat from the effects of vibration and road-shock.