The influence of operator driving characteristics in whole-body vibration exposure from electrical fork-lift trucks

Occupational exposure to whole-body vibration has been pointed out as one of the major occupational risk factors in workplaces where vehicles are used by the workers. In some electrical fork-lifts vehicles, such as those generally called stackers, operators are requested to operate the vehicle in the upright position. Vibration exposure in this type of vehicles is rarely documented. Besides, stackers present some characteristics that could be potentially inadequate regarding operators’ ergonomics. Due to the electrical powered motors, these vehicles can be operated with fast and sudden movements. The aim of this study was to characterize vibration exposure within these vehicles and to analyse the vibration exposure associated with the operation of these vehicles and to understand how individual characteristics, such as weight, age, experience, training and dexterity, can affect stacker vibration exposure levels. Vibration measurements were conducted considering a pre-defined task and a sample of 10 operators working with two different models of electrical stackers. In order to assess operators’ postures, as well as other individual variables, an individual questionnaire was undertaken. The results obtained seem to indicate that the dexterity and experience in driving such vehicles increase the vibration exposure levels. Besides, handling of this type of vehicle frequently forces the operator to adopt inadequate postures, because the stacker is often driven in a standing up position. One of those postures is the rotation of the torso, which, coupled with whole-body vibration exposure, may result in an increased risk of lumbar and back musculoskeletal disorders