Assessing the impact of log manual loading on the physiological load in forest wokers

Despite progress in full mechanization, motor-manual logging technologies still dominate in many countries, including in North plantation forest of Iran. Motor-manual timber harvesting is considered to be one of the most dangerous working operations. The physical demands of work are still one of the crucial workload factors in most jobs in the forestry sector, especially those connected to manual loading. The aim of the study was to investigate the physiological workload of a worker during manual loading in a poplar plantation stand in the north of Iran. Physiological responses were assessed on a sample of 12 workers manual loading during a normal working shift. Polar heart rate monitors were fitted over a period of a week in order to record ‘working’ heart rates. The collected data were used for the calculation of heart rate indices that determine the strain of the subjects. The average mean heart rates during work time, rest time, and maximum heart rate were 132.42, 79.42, and 175.16 bpm respectively. The results showed that the mean level of physical workload was 55 which correspond to very heavy work. The study results also showed that age and body mass index of workers is significantly effective on HRw and weight of workers on HRw and HRmax, respectively. The results revealed high physiological demands of manual loading. Increasing the mechanization level with investment in modern equipment may be proving beneficial in enhancing workers health and safety.