Number of Workers for Assessing Physiological Workload while Operating Farm Equipment

Physiological cost of operation is indirectly measured either with heart rate or oxygen consumption in a particular activity by workers (subjects) and expressed in terms of heart rate and oxygen consumption rate. Classification of physical work according to severity of work load is done on the basis of heart rate or volume of oxygen consumption rate or energy expenditure rate of individual farm women and that operation can be categorized in very light ((91–105 beats per minute), moderate heavy (106–120 beats per minute), heavy (121–135 beats per minute), very heavy (136–150 beats per minute) and extremely heavy workload (> 151 beats per minute). The physiological workload varied for same activity or farm operations under similar environment with every individual due to different level of her capacity. Due to this reason, the number of subjects for each activity is very important so that average physiological workload of that activity performed by subject could be assessed.

No such exercise has been made so far to quantify the number of subjects for an activity to be assessed physiologically. In the paper an attempt has been made to analyse the heart rate data of 296 participated subjects whose age varied from 23 to 60 years for 32 different activities in span of 8 years for assessing the number of subjects in an activity using statistics considering the number of subjects as replication. The SEM analysis indicates minimum number of subjects should be eight for assessment of light workload category while 12–13 numbers of subjects for assessing rest of physiological workload.