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Effect of terrain on the energy cost of walking with back loads and hand-cart loads
digital computers, for which a complex and voluminous 'real-time' software has had to be compiled and brought up-to-date without interrupting the procedure. It is ir~ visualizing the total pattern that the most difficult problems arise because the major decisions determining the success or failure of the operation have had to be taken without the possibility of acquiring any preliminary experience. 6.3.7 (66969) Drury, C.G. The inspection of sheet materials model and data. In: Proceedings of the Seventeenth Annual Meeting of the Human Factors Society, 1 6 - 1 8 Oct, 1973. In the inspection of sheet materials in industry two interrelated tasks are involved: visual search and decision making. When these tasks have been studied separately in laboratories it has been found that b o t h exhibit a speed/error trade-off. As more time is allowed for the task errors usually decrease. However, the speed/error trade-off in industrial inspection studies shows that as time per item is increased, while Type 2 errors decrease, T y p e 1 errors actually increase. A model combining visual search and decision theory is postulated and tested on the inspection of flat glass for discrete faults. Separate experiments are performed to test the ability of inspectors to (a) search for and locate known defects in sheets of glass and (b) decide whether a small fixated circular dot is above or below the standard required. The results of these two experiments are used to derive model parameters and the model used to predict performance in the factory situation. The model predictions are of the same form as results obtained previously in flat glass inspection.
Factors affecting perceptual-motor processes 6.3.8
(66994)
standards be established for cashregister operators.
6.3.9
(67279)
Rohmert, W. and Luczak, H. Determination of work load in field studies: evaluation and design of an inspection task. (Determination de la Charge de Travail sur le Terrain: Evaluation et Amenagment d'une Tache D'Inspection). (In French) Travail Humain, Jan 1974, 37.1, 147-164. A method of analysis of work load for experimental field studies is presented. The complex term 'workload' is split into more operable and measurable items that are connected by an analytical concept. As an example of application, a visual inspection task of bottles in a brewery is analysed. The results of the field study indicate that the human operator in this task is loaded/stressed above the endurance limits. An appropriate design of the work system is proposed to reduce stress. This design approach takes into account technological, ergonomic and organizational aspects.
Physiology, anthropometry and biomechanics 6.3.10 (67020)
Morgan, W.K.C. et al Ventilatory capacity and lung volumes of US coal miners.
Archives o f Environmental Health, Apr 1974, 28.4, 1 8 2 - 1 8 9 . Abstr in: CIS Abstracts (CIS 7 4 - 1 7 2 2 ) Lung volumes and ventilatory capacity of 9076 coal miners were determined during the period 1 9 6 9 1971. The data collected indicates that while coal mining may in certain instances lead to very minor reductions of ventilatory capacity, such reductions are minimal in the absence of complicated pneumoconiosis and would not be associated with respiratory disability.
Nishiyama, K., Nakaseko, M. and Hosokawa, M. Cash register operators' work and its hygienic problems in a supermarket.
Japanese Journal o f Industrial Health, May 1973, 1 5 . 3 , 2 2 9 - 2 4 3 . Health examinations of 27 cashregister operators were carried out and their workloads evaluated. The results of the investigation show that the mental and physical workloads involved may cause chronic irreversible fatigue and ultimate disease. It is recommended that safety and hygiene
6.3.11 (67027)
Morrison, J.F. and Blake, G.T.W. Physiological observations on cane cutters. European Journal o f A pplied
Physiology and Occupational Physiology, 1974, 33.3, 2 4 7 - 2 5 4 . Oxygen consumption and output measurements were made to determine the mechanical efficiency of Australian and Rhodesian cane cutters. It was found that those Rhodesian cutters who had changed to a more
upright stance and attained the maximum momentum of the cane knife, increased their output by 30%. The Australian cane cutters who use a better designed and sharper knife and a cutting technique in which they handle more stalks at a time, achieve an even greater degree of efficiency than the more efficient Rhodesian cutters. The study has also shown that a higher than average maximum oxygen consumption is an advantage when high output levels are required.
6.3.12 (67036)
Haisman, M.F. and Goldman, R.F. Effect of terrain on the energy cost of walking with back loads and handcart loads. Journal of Applied Physiology, May 1974, 3 6 . 5 , 5 4 5 - 5 4 8 . Previous work established that moving heavy loads by cart on a smooth surface required a lower energy cost than the same load on the back. However, the effect of uneven terrain on this energy cost differential had not to the authors' knowledge been studied systematically. Eight young soldiers carried a 20 kg back load (additional to clothing and respirometer) or pulled a handcart weighing 20, 60, or 100 kg, at two speeds (0.89 or 1.34 m/s) on three terrains (blacktop road, dirt road, or grassland) in a randomized factorial design. Energy cost was measured three times during each 30 min walk. The results indicated that although on a smooth surface the 100 kg cart is no more costly than a 20 kg backpack, on b o t h uneven terrains only the 20 kg cart was equivalent to a 20 kg back load. Nonetheless, the energy cost of moving the 100 kg cart over these uneven terrains, at these speeds, was within acceptable physiological limits for these subjects, although this would probably not be the case with more difficult terrains such as soft sand or heavy brush.
6.3.13 (67042)
Bullock, M.I. The physiotherapist's role in the control of industrial injuries. Control, Nov 1974, 1.2, 6 9 - 7 5 . The physiotherapist has a large part to play in the modern industrial scene and contibutes to the control of injury and production loss in many ways. These include the appraisal of the worker's physical limitations, his proper placement in employment according to job assessment, the promotion of physical fitness, maintenance of suitable man-machinetask relationships and of good working postures, the efficient and effective
Applied Ergonomics September 1975
181
Factors affecting perceptual-motor processes 6.3.8
(66994)
standards be established for cashregister operators.
6.3.9
(67279)
Rohmert, W. and Luczak, H. Determination of work load in field studies: evaluation and design of an inspection task. (Determination de la Charge de Travail sur le Terrain: Evaluation et Amenagment d'une Tache D'Inspection). (In French) Travail Humain, Jan 1974, 37.1, 147-164. A method of analysis of work load for experimental field studies is presented. The complex term 'workload' is split into more operable and measurable items that are connected by an analytical concept. As an example of application, a visual inspection task of bottles in a brewery is analysed. The results of the field study indicate that the human operator in this task is loaded/stressed above the endurance limits. An appropriate design of the work system is proposed to reduce stress. This design approach takes into account technological, ergonomic and organizational aspects.
Physiology, anthropometry and biomechanics 6.3.10 (67020)
Morgan, W.K.C. et al Ventilatory capacity and lung volumes of US coal miners.
Archives o f Environmental Health, Apr 1974, 28.4, 1 8 2 - 1 8 9 . Abstr in: CIS Abstracts (CIS 7 4 - 1 7 2 2 ) Lung volumes and ventilatory capacity of 9076 coal miners were determined during the period 1 9 6 9 1971. The data collected indicates that while coal mining may in certain instances lead to very minor reductions of ventilatory capacity, such reductions are minimal in the absence of complicated pneumoconiosis and would not be associated with respiratory disability.
Nishiyama, K., Nakaseko, M. and Hosokawa, M. Cash register operators' work and its hygienic problems in a supermarket.
Japanese Journal o f Industrial Health, May 1973, 1 5 . 3 , 2 2 9 - 2 4 3 . Health examinations of 27 cashregister operators were carried out and their workloads evaluated. The results of the investigation show that the mental and physical workloads involved may cause chronic irreversible fatigue and ultimate disease. It is recommended that safety and hygiene
6.3.11 (67027)
Morrison, J.F. and Blake, G.T.W. Physiological observations on cane cutters. European Journal o f A pplied
Physiology and Occupational Physiology, 1974, 33.3, 2 4 7 - 2 5 4 . Oxygen consumption and output measurements were made to determine the mechanical efficiency of Australian and Rhodesian cane cutters. It was found that those Rhodesian cutters who had changed to a more
upright stance and attained the maximum momentum of the cane knife, increased their output by 30%. The Australian cane cutters who use a better designed and sharper knife and a cutting technique in which they handle more stalks at a time, achieve an even greater degree of efficiency than the more efficient Rhodesian cutters. The study has also shown that a higher than average maximum oxygen consumption is an advantage when high output levels are required.
6.3.12 (67036)
Haisman, M.F. and Goldman, R.F. Effect of terrain on the energy cost of walking with back loads and handcart loads. Journal of Applied Physiology, May 1974, 3 6 . 5 , 5 4 5 - 5 4 8 . Previous work established that moving heavy loads by cart on a smooth surface required a lower energy cost than the same load on the back. However, the effect of uneven terrain on this energy cost differential had not to the authors' knowledge been studied systematically. Eight young soldiers carried a 20 kg back load (additional to clothing and respirometer) or pulled a handcart weighing 20, 60, or 100 kg, at two speeds (0.89 or 1.34 m/s) on three terrains (blacktop road, dirt road, or grassland) in a randomized factorial design. Energy cost was measured three times during each 30 min walk. The results indicated that although on a smooth surface the 100 kg cart is no more costly than a 20 kg backpack, on b o t h uneven terrains only the 20 kg cart was equivalent to a 20 kg back load. Nonetheless, the energy cost of moving the 100 kg cart over these uneven terrains, at these speeds, was within acceptable physiological limits for these subjects, although this would probably not be the case with more difficult terrains such as soft sand or heavy brush.
6.3.13 (67042)
Bullock, M.I. The physiotherapist's role in the control of industrial injuries. Control, Nov 1974, 1.2, 6 9 - 7 5 . The physiotherapist has a large part to play in the modern industrial scene and contibutes to the control of injury and production loss in many ways. These include the appraisal of the worker's physical limitations, his proper placement in employment according to job assessment, the promotion of physical fitness, maintenance of suitable man-machinetask relationships and of good working postures, the efficient and effective
Applied Ergonomics September 1975
181