Anthropometry and physical work capacity of agricultural laborers in Thailand

Research was conducted on selective man-machine-environment aspects of human engineering in relation to agricultural laborers. Anthropometric data and static strength of agricultural laborers were collected and measured. Laboratory experiments were conducted to estimate the physical work capacity of the laborers. Physical work load for land preparation, planting, harvesting and weeding was evaluated. Forty-four body dimensions were measured for 50 male and 50 female laborers. The average body dimensions, standard deviation and 5th, 10th, 90th, 95th percentile were determined. No significant difference was observed in most of the body dimensions of laborers in different age groups for both female and male subjects. Body dimensions of length were in a constant proportion to stature. The static strength of back, arm, leg, shoulder, composite and hand grip for males were 70.9, 42.9, 113.1, 62.7, 116.6, 36.4 kg, respectively and corresponding values for females were 47.1, 28.9, 73.4, 31.0, 68.1, and 18.6 kg, respectively. Static strength was found to decrease with increasing age for both male and female laborers. Correlation was determined for age, weight, height and heart rate with physical work capacity. The average physical work capacity for male and female laborers were 2.07+-0.57 l/min and 1.38+-0.23 l/min, respectively. The physical work capacity for females was 66.42 % of that of males. Oxygen consumption, heart rate and pulmonary ventilation were measured to determine the physical work load on four male and four female laborers during the four farm operations. The physical work load for land preparation, planting, weeding and harvesting operations, expressed in percent VO2 max, was 44 %, 41 %, 30 %, 44%, respectively. Land preparation was found to be the heaviest work and other operations as moderate work. Relation between physical work load and environment was established which indicated that relative humidity had the greatest impact on physical work load. Postural discomfort was higher for land preparation than for other operations.