Heart rate strain in cable hauler choker setters in New Zealand logging operations

This study examined the physical strain experienced by cable hauler choker setters, and the applicability of heart rate indices for measuring physical strain in commercial forest harvesting operations in New Zealand. The hear t rate of four choker setters were recorded continuously throughout the wor king day and applied to heart rate indices. Based on the relative heart rat e at work (%HRR), ratio of working heart rate to resting heart rate and 50% level indices, the mean working heart rate (HRw) of 106 bt. min(-1) +/- 6. 9 (mean +/- SD) placed choker setting in the moderate workload category. Th e specific tasks of line shifts (120.3 +/- 4.8 bt. min(-1)), hooking up dra gs (118.8 +/- 6.6 bt. min(-1)) and uphill travel (126.1 +/- 12.9 bt. min(-1 )), imposed the most severe workloads on the choker setters. This research also demonstrated that heart rate indices could be used as an effective mea ns of determining the physiological strain of subjects working in New Zeala nd's commercial forest harvesting operations. (C) 2001 Published by Elsevie r Science Ltd.