Whole body vibration and the snowmobile.

The whole body vibration from the seat and foot board was measured during ten years from 11 different snowmobiles to evaluate the exposure and the need for technical improvements. In a questionnaire more than half of the drivers had back pains but only a few of them considered the whole body vibration as a health hazard. However in the literature there is often comments on spinal injuries related to shock vibration. The frequency-weighted acceleration of snowmobile vibration was from 1 to 6.1 m/s2 and the risk evaluation using the ISO standard predicted the problems. Speed and the unevenness of the driving terrain caused vibration. The damping depends on the properties of the seat, terrain and speed limits. Also the driving posture is important. Especially on the snowmobile tracks the whole body vibration was high and according to modern knowledge more attention should be paid the technical properties of snowmobiles.