Relationship between health complaints and exposure to trembling and shaking during work. Particular experiences with heavy tools and engines concerning trembling and shaking and during driving a bus or a tram / regularity of technical control of tools and engines / time spent at working with heavy tools and engines, at present and in the past, during work and during leisure time / technical training / working pressure / satisfaction about work / being troubled by the effects of working with heavy tools and engines / kind of physical efforts during work / having back-pain, neck-pain, pain and stiffness of limbs, tingling in hands and fingers, as well as during work as after work / checking of other general health problems / smoking behaviour / r's own judgement of relationship between physical complaints and type of work / discussing physical complaints with company doctor / length and weight of respondent. Background variables: basic characteristics/ occupation/employment