An Ergonomic Evaluation of Douglas Fir Manual Pruning in New Zealand
Authors
P. M. Kirk
New Zealand Logging Industry, Research Organisation, Rotorua, New Zealand
R. J. Parker
New Zealand Logging Industry, Research Organisation, Rotorua, New Zealand
Abstract
This report summarizes the findings of an ergonomie evaluation of first lift manual pruning of Douglas fir under New Zealand plantation forestry conditions. Six subjects were each observed undertaking their normal work methods throughout their complete working day. Heart rate data were collected and analysed using several heart rate indices in order to determine the workload of first lift pruning. The average working heart rate was 112 bt.min"1 ± 10.6 (SD). Results indicate first lift pruning to be a moderate to heavy workload activity. The manual pruning work method may place severe pressures on the workers' tendons, related bones and nerves of the hand, wrist, and elbow. Alternative pruning methods may contain inherent health and safety risks which must be carefully considered by those involved in the occupation of professional tree pruning.
