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A physiological study of manual lifting of loads in Indians
13.4.12 (82243)
Gasie, M. Anthropometric dimensions and the height of the working surface for work in a standing position. In: Proceedings
resulted in an optimum load of about 17 kg. The percentage 'credit' given to the body mass itself depends on how important it is that the carrier does not arrive fatigued at his destination. The military may wish to give 100% credit, and recreational carriers zero.
of the XIX International Congress on Occupational Health, Dubrovnik, Yugoslavia, 25-30 Sep 1978, Edited by R. Plestintt Institute for Medical 13.4.14 (82259) Research and Occupational Health, Zagreb, Yugoslavia, 1980, 3, 1253-1257. Samanta, A., and Chatterjee, B.B. A physiological study of manual lifting In order to establish the optimum of loads in Indians. Ergonomics, Jul height of the working surfaces of machines and working benches for males working in a standing position, the relevant anthropometric dimensions were used as the starting base. Using as sample 203 males, of an average age of 29, measures were made of 12 relevant longitudinal anthropometric variables, and the obtained data were statistically elaborated. On the basis of the analysed results of this investigation, and taking into consideration the current ergonomic principles established for certain working positions, and especially for a standing working position, the optimum heights for certain types of work are defined as well as the optimum heights of the working surfaces of machines and working benches for males working in a standing position. The necessity is pointed out of providing a foot grid or some other raised support for workers with shorter longitudinal dimensions in order to improve and adjust their relation to the actual height of the machines and working surfaces. 13.4.13 (82257)
Pierrynowski, M.R., Winter, D.A., and Norman, R.W. Metabolic measures to ascertain the optimal load to be carried by man. Ergonomics, May 1981, 2 4 . 5 , 3 9 3 399. As part of a combined electromyographic, mechanical work and metabolic study of load carriage, this research focuses on the optimal load carried by the subject. This study demonstrates the anomalies associated with the definition of optimal load, and shows that it is dependent on whether or not the carrier is given any credit for carrying his own weight as well as that of the load. In many situations it may be important to include the carrier's own b o d y mass in the optimal load equation. This study showed that if the load were body plus backpack the optimal backpack load was found to be quite low (less than 10 kg) because the metabolic cost increased quite rapidly at low loads. On the other hand, if the carrier's mass was ignored there might be an optimum load at 40 kg or higher. Giving partial 'credit' for carrying body weight (for example, 50% b o d y mass plus backpack),
1981, 2 4 . 7 , 5 5 7 - 5 6 4 . The employment of workers solely for lifting of loads is common in the developing countries. This task can be described in terms of its three principal variables, viz, the weight of the load, the height of the lift and the rate of lifting, but few attempts have been made to quantify the contributions of these variables in determining its strenuousness. Based on the observed range of variation in an industrial lifting operation, a total of 525 lifting experiments comprising combinations of three different weights of compact loads, lifts to three separate heights from the ground level, and three different rates of lifting were carried out on 21 subjects selected from amongst the load lifters. Comparison of the observed energy expenditures of these tasks with the maximum working capacities of the subjects showed that many of the tasks were unduly heavy. Regression equations depicting the relation between the energy expenditure of lifts of different heights with the other two variables are given. A chart linking these variables has also been prepared; this may be helpful in adjusting those lifting tasks which are continued for prolonged periods so that they are of 'acceptable' heaviness. 13.4.15 (82274)
Itani, T., et al Occupational hazard of female film rolling workers and effects of improved working conditions. In: Proceedings of
the XIX International Congress on Occupational Health, Dubrovnik, Yugoslavia, 25-30 Sep 1978, Edited by R. Plestina Institute for Medical Research and Occupational Health, Zagreb, Yugoslavia, 1980, 3, 1 2 4 3 1251. Occurrence of occupational hazard in the neck-shoulder-arm region was investigated before and after improvement of working conditions of female photographic film roiling workers, who were exposed to repetitive upper limb loading relevant to occupational disorders of keyboard operators. The workers were daily engaged in the manual handling of 35 mm colour films in dark rooms; group A workers
worked separately, receiving automatically rolled films and canning them by a capping machine, and group B workers operated either a winding or capping machine along a conveyor line, holding the film with hands. Annual health examinations centering on occupational cervicobrachial disorders were carried out in 1 9 7 5 - 1 9 7 7 . In 1975, when the workers worked for 440 min a day with a 60 min lunch recess and a morning and afternoon rest of 5 rain, percentages of workers with the disorder of grade I (local pain), grade II (muscle rigidity or tenderness), and grade III (enlargement of affected regions with lower muscle strength and neurologic signs) were 38, 22, and 13% of 45 workers in group A and 43, 40, and 11% of 53 workers in group B. As preventive measures of the disorder suggested by previous studies, the actual operation time of these workers was reduced by 1976 from 353 min to 330 min per day, the number of rest periods other than lunch recess was increased six times and a continuous operating time was reduced from 105 min to 55 rain. The designing of seats and capping machines also improved and group B workers began to operate the winding operations every third or fourth day. Health examinations repeated in 1977 disclosed that the rate of workers with grades I, II, and III of occupational cerviobrachial disorders decreased to 33, 13, and 7% in 61 workers of group A and to 34, 20, and 8% in 64 workers of group B, respectively. Of 38 group A and 43 group B workers examined both in 1975 and 1977, 45% of group A and 44% of group B were found to have a lesser degree of the hazard, 11% of group A and 19% of group B being at an aggravated risk. The results clearly suggest that local muscular loading by repetitive upper limb operations which involve the handling of small objects may lead to occupational hazard, and that improvement of working conditions, in particular a greater number of minor rest periods and reduced continuous operation time, are vital in preventing such occupational hazard. 13.4.16 (82276)
Mito, H. et al Problems that cause health hazards to supermarket cash register operators. In: Proceedings of the XIX International
Congress on Occupational Health, Dubrovnik, Yugoslavia, 25-30 Sep 1978, Edited by R. Plestina, Institute for Medical Research and Occupational Health, Zagreb, Yugoslavia, 1980, 3, 1259-1269. With the rapidly increasing number of department stores since 1970, health disorders (occupational cervieobrachial
Applied Ergonomics December 1982
307
Gasie, M. Anthropometric dimensions and the height of the working surface for work in a standing position. In: Proceedings
resulted in an optimum load of about 17 kg. The percentage 'credit' given to the body mass itself depends on how important it is that the carrier does not arrive fatigued at his destination. The military may wish to give 100% credit, and recreational carriers zero.
of the XIX International Congress on Occupational Health, Dubrovnik, Yugoslavia, 25-30 Sep 1978, Edited by R. Plestintt Institute for Medical 13.4.14 (82259) Research and Occupational Health, Zagreb, Yugoslavia, 1980, 3, 1253-1257. Samanta, A., and Chatterjee, B.B. A physiological study of manual lifting In order to establish the optimum of loads in Indians. Ergonomics, Jul height of the working surfaces of machines and working benches for males working in a standing position, the relevant anthropometric dimensions were used as the starting base. Using as sample 203 males, of an average age of 29, measures were made of 12 relevant longitudinal anthropometric variables, and the obtained data were statistically elaborated. On the basis of the analysed results of this investigation, and taking into consideration the current ergonomic principles established for certain working positions, and especially for a standing working position, the optimum heights for certain types of work are defined as well as the optimum heights of the working surfaces of machines and working benches for males working in a standing position. The necessity is pointed out of providing a foot grid or some other raised support for workers with shorter longitudinal dimensions in order to improve and adjust their relation to the actual height of the machines and working surfaces. 13.4.13 (82257)
Pierrynowski, M.R., Winter, D.A., and Norman, R.W. Metabolic measures to ascertain the optimal load to be carried by man. Ergonomics, May 1981, 2 4 . 5 , 3 9 3 399. As part of a combined electromyographic, mechanical work and metabolic study of load carriage, this research focuses on the optimal load carried by the subject. This study demonstrates the anomalies associated with the definition of optimal load, and shows that it is dependent on whether or not the carrier is given any credit for carrying his own weight as well as that of the load. In many situations it may be important to include the carrier's own b o d y mass in the optimal load equation. This study showed that if the load were body plus backpack the optimal backpack load was found to be quite low (less than 10 kg) because the metabolic cost increased quite rapidly at low loads. On the other hand, if the carrier's mass was ignored there might be an optimum load at 40 kg or higher. Giving partial 'credit' for carrying body weight (for example, 50% b o d y mass plus backpack),
1981, 2 4 . 7 , 5 5 7 - 5 6 4 . The employment of workers solely for lifting of loads is common in the developing countries. This task can be described in terms of its three principal variables, viz, the weight of the load, the height of the lift and the rate of lifting, but few attempts have been made to quantify the contributions of these variables in determining its strenuousness. Based on the observed range of variation in an industrial lifting operation, a total of 525 lifting experiments comprising combinations of three different weights of compact loads, lifts to three separate heights from the ground level, and three different rates of lifting were carried out on 21 subjects selected from amongst the load lifters. Comparison of the observed energy expenditures of these tasks with the maximum working capacities of the subjects showed that many of the tasks were unduly heavy. Regression equations depicting the relation between the energy expenditure of lifts of different heights with the other two variables are given. A chart linking these variables has also been prepared; this may be helpful in adjusting those lifting tasks which are continued for prolonged periods so that they are of 'acceptable' heaviness. 13.4.15 (82274)
Itani, T., et al Occupational hazard of female film rolling workers and effects of improved working conditions. In: Proceedings of
the XIX International Congress on Occupational Health, Dubrovnik, Yugoslavia, 25-30 Sep 1978, Edited by R. Plestina Institute for Medical Research and Occupational Health, Zagreb, Yugoslavia, 1980, 3, 1 2 4 3 1251. Occurrence of occupational hazard in the neck-shoulder-arm region was investigated before and after improvement of working conditions of female photographic film roiling workers, who were exposed to repetitive upper limb loading relevant to occupational disorders of keyboard operators. The workers were daily engaged in the manual handling of 35 mm colour films in dark rooms; group A workers
worked separately, receiving automatically rolled films and canning them by a capping machine, and group B workers operated either a winding or capping machine along a conveyor line, holding the film with hands. Annual health examinations centering on occupational cervicobrachial disorders were carried out in 1 9 7 5 - 1 9 7 7 . In 1975, when the workers worked for 440 min a day with a 60 min lunch recess and a morning and afternoon rest of 5 rain, percentages of workers with the disorder of grade I (local pain), grade II (muscle rigidity or tenderness), and grade III (enlargement of affected regions with lower muscle strength and neurologic signs) were 38, 22, and 13% of 45 workers in group A and 43, 40, and 11% of 53 workers in group B. As preventive measures of the disorder suggested by previous studies, the actual operation time of these workers was reduced by 1976 from 353 min to 330 min per day, the number of rest periods other than lunch recess was increased six times and a continuous operating time was reduced from 105 min to 55 rain. The designing of seats and capping machines also improved and group B workers began to operate the winding operations every third or fourth day. Health examinations repeated in 1977 disclosed that the rate of workers with grades I, II, and III of occupational cerviobrachial disorders decreased to 33, 13, and 7% in 61 workers of group A and to 34, 20, and 8% in 64 workers of group B, respectively. Of 38 group A and 43 group B workers examined both in 1975 and 1977, 45% of group A and 44% of group B were found to have a lesser degree of the hazard, 11% of group A and 19% of group B being at an aggravated risk. The results clearly suggest that local muscular loading by repetitive upper limb operations which involve the handling of small objects may lead to occupational hazard, and that improvement of working conditions, in particular a greater number of minor rest periods and reduced continuous operation time, are vital in preventing such occupational hazard. 13.4.16 (82276)
Mito, H. et al Problems that cause health hazards to supermarket cash register operators. In: Proceedings of the XIX International
Congress on Occupational Health, Dubrovnik, Yugoslavia, 25-30 Sep 1978, Edited by R. Plestina, Institute for Medical Research and Occupational Health, Zagreb, Yugoslavia, 1980, 3, 1259-1269. With the rapidly increasing number of department stores since 1970, health disorders (occupational cervieobrachial
Applied Ergonomics December 1982
307