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Evaluation of methodology for evaluating lighting for offices with VDTs
careful use of the term 'handrail', thereby clarifying that handrails are a special class of railings, that are appropriately sized, shaped, located and supported to help arrest serious, injury-producing falls - especially on stairs, the leading site of accidents in buildings. 19.3.25 (107454)
Martinez, J.R. Ergonomics in the fast food industry: A vehicle to increase productivity. In: Trends in Ergonomics/Human Factors IV, Proc Ann Int Indust Erg and Safety Conf, Miami, USA, 9 - 1 2 June 1987, S.S. Asfour (Ed). North-Holland, Amsterdam, 1987, pp 5 5 - 6 4 . Considering the h u m a n factors involved in the working environment of a fast food restaurant has proven to be a rewarding experience. Rewarding in the sense of productivity increases. This paper covers the application of simple ergonomics principles to the design of a workstation. The primary focus for reaching design decisions was the worker. Therefore, the first factor or first component of the design was the workers. Anthropometric capabilities of them were considered to determine the physical characteristics of the station. Characteristics such as work surface height, width and depth, and component location, must be designed for maximum worker comfort and productivity. Even sitting down employees at the workstation, an option radical for the fast food industry, was considered. An analysis of the benefits and drawbacks of doing this is shown. Upon reaching a design that was optimal for one operator, functional design factors were considered, so that the final design would be operationally flexible. Productivity results of the final design were significant. These results are a clear indication that considering the ergonomics involved in fast food operations is a vehicle to increase productivity.
19.3.26 (106468)
Dainoff, M.J., and Mark, L.S. Task and the adjustment of ergonomic chairs. In: Work with Display Units 86, B. Knave and P.G. Wideback (Eds). North-Holland, Amsterdam, 1987, pp 2 9 4 - 3 0 2 . Studies evaluating the effectiveness of ergonomic chairs often fail to consider how the task affects workers' postural demands. In the light of the different physical demands of various jobs performed at VDUs, it is highly unlikely that a single posture would suffice across tasks. Moreover, movement is essential for maintaining a stable sitting posture for prolonged periods of time, in order to avoid skeletal and
muscular discomfort as well as circulatory problems resulting from diminished blood flow to areas supporting body weight. The current study investigates the influence of task requirements on the effectiveness of forward and backward tilt mechanisms on ergonomic chairs. Experienced clerical workers were provided with information concerning the postural requirements for sitting and were trained in adjusting an ergonomic chair, which could assume both forward and backward tilt positions. Subjects alternately performed data entry and verification tasks in 30 min sessions for periods of 3 h each day for 5 days. Adjustments of the chair and body posture were continuously monitored to determine how often subjects adjusted the chair configuration and working posture. These adjustments were compared with measures of task performance and body comfort. Analyses were designed to determine: whether subjects, when given the opportunity to utilise adjustable furniture, would take advantage of these features; the temporal period from one adjustment to another; and whether certain postures were more effective for particular tasks than other postures.
19.3.27 (107475)
Mandal, A.C. The influence of furniture height on backpain. Behaviour and Inf Tech, 1987, 6 . 3 , 3 4 7 - 3 5 2 . Modern office furniture is constructed in such a way that nobody is able to use it correctly. Each day people sit for many hours hunched over their tables in positions harmful to the back. The main reason for this seems to be the low, backward sloping seats, which represent an effective hindrance to all types of work over the table. This naturally leads to pronounced flexion and strain of the back and neck. A higher, forward sloping seat will tend to reduce the flexion and strain of the back and bring the person into a more upright balanced position with a greater open angle between th~ body and the thighs. This resembles the position taken when sitting on horseback. In an experiment with data-entry personnel suffering from chronic back-pain, furniture was adjusted to a height which the subjects found most comfortable. On average, they preferred to sit at a table 6"6 cm higher than recommended by European Standardisation (CEN). This higher position can only be used when sitting on a forward sloping seat. The pain indication (Huskisson, 1974) was for the Standard furniture 67 mm compared with 35 mm on the higher furniture. The flexion of the back was
reduced from 75 ° to 64 ° . The evaluation was made after a two.month trial period. 19.3.28 (107488)
Challis, P.B. The development of performance standards for equipment used by disabled people. In: Ergonomics in New Zealand, Proc Inaugural Conf NZ Erg Soc, Auckland, February 1987. New Zealand Ergonomics Society, 1987, pp 157-167. In developing national standards for equipment it is important that the requirements do not limit the design and manufacture process. The author has been involved in developing standards for two pieces of equipment used by disabled people. This paper outlines the main philosophies used and presents a case study of a wheelchair standard.
Environment 19.3.29 (106494)
Goodwin, P.E. Evaluation of methodology for evaluating lighting for offices with VDTs. J Illum Eng Soc, 1987, 16.1, 39-48. Twenty-eight observers evaluated VDT screens under six representative lighting systems. Subsequent evaluation of photographs of the VDTs by these observers revealed a very high and statistically significant correlation between the two methods. These results indicate that this more efficient methodology may be used to examine many important parameters. 19.3.30 (107493)
European Coal and Steel Community Guidelines on the ergonomics of underground illumination in coal mines. ECSC, Community Ergonomics Action, Luxembourg, Report No 9 Series 3, 1987, 49 pp. The guidelines presented in this document are based on ergonomics studies of the lighting requirements in coal mines carried out by member industries of the European Coal and Steel Community. They deal only with the ergonomics considerations covering the relationship between the worker, his task and lighting provision in terms of both safety and performance. They are presented as a practical distillation of current ergonomics knowledge to supplement the specialist engineering skills of lighting and electrical engineers in designing improved lighting installations. The guidelines are presented in two sections: Section 1 covers the general philosophy, objectives and
Applied Ergonomics
September1988
245
Martinez, J.R. Ergonomics in the fast food industry: A vehicle to increase productivity. In: Trends in Ergonomics/Human Factors IV, Proc Ann Int Indust Erg and Safety Conf, Miami, USA, 9 - 1 2 June 1987, S.S. Asfour (Ed). North-Holland, Amsterdam, 1987, pp 5 5 - 6 4 . Considering the h u m a n factors involved in the working environment of a fast food restaurant has proven to be a rewarding experience. Rewarding in the sense of productivity increases. This paper covers the application of simple ergonomics principles to the design of a workstation. The primary focus for reaching design decisions was the worker. Therefore, the first factor or first component of the design was the workers. Anthropometric capabilities of them were considered to determine the physical characteristics of the station. Characteristics such as work surface height, width and depth, and component location, must be designed for maximum worker comfort and productivity. Even sitting down employees at the workstation, an option radical for the fast food industry, was considered. An analysis of the benefits and drawbacks of doing this is shown. Upon reaching a design that was optimal for one operator, functional design factors were considered, so that the final design would be operationally flexible. Productivity results of the final design were significant. These results are a clear indication that considering the ergonomics involved in fast food operations is a vehicle to increase productivity.
19.3.26 (106468)
Dainoff, M.J., and Mark, L.S. Task and the adjustment of ergonomic chairs. In: Work with Display Units 86, B. Knave and P.G. Wideback (Eds). North-Holland, Amsterdam, 1987, pp 2 9 4 - 3 0 2 . Studies evaluating the effectiveness of ergonomic chairs often fail to consider how the task affects workers' postural demands. In the light of the different physical demands of various jobs performed at VDUs, it is highly unlikely that a single posture would suffice across tasks. Moreover, movement is essential for maintaining a stable sitting posture for prolonged periods of time, in order to avoid skeletal and
muscular discomfort as well as circulatory problems resulting from diminished blood flow to areas supporting body weight. The current study investigates the influence of task requirements on the effectiveness of forward and backward tilt mechanisms on ergonomic chairs. Experienced clerical workers were provided with information concerning the postural requirements for sitting and were trained in adjusting an ergonomic chair, which could assume both forward and backward tilt positions. Subjects alternately performed data entry and verification tasks in 30 min sessions for periods of 3 h each day for 5 days. Adjustments of the chair and body posture were continuously monitored to determine how often subjects adjusted the chair configuration and working posture. These adjustments were compared with measures of task performance and body comfort. Analyses were designed to determine: whether subjects, when given the opportunity to utilise adjustable furniture, would take advantage of these features; the temporal period from one adjustment to another; and whether certain postures were more effective for particular tasks than other postures.
19.3.27 (107475)
Mandal, A.C. The influence of furniture height on backpain. Behaviour and Inf Tech, 1987, 6 . 3 , 3 4 7 - 3 5 2 . Modern office furniture is constructed in such a way that nobody is able to use it correctly. Each day people sit for many hours hunched over their tables in positions harmful to the back. The main reason for this seems to be the low, backward sloping seats, which represent an effective hindrance to all types of work over the table. This naturally leads to pronounced flexion and strain of the back and neck. A higher, forward sloping seat will tend to reduce the flexion and strain of the back and bring the person into a more upright balanced position with a greater open angle between th~ body and the thighs. This resembles the position taken when sitting on horseback. In an experiment with data-entry personnel suffering from chronic back-pain, furniture was adjusted to a height which the subjects found most comfortable. On average, they preferred to sit at a table 6"6 cm higher than recommended by European Standardisation (CEN). This higher position can only be used when sitting on a forward sloping seat. The pain indication (Huskisson, 1974) was for the Standard furniture 67 mm compared with 35 mm on the higher furniture. The flexion of the back was
reduced from 75 ° to 64 ° . The evaluation was made after a two.month trial period. 19.3.28 (107488)
Challis, P.B. The development of performance standards for equipment used by disabled people. In: Ergonomics in New Zealand, Proc Inaugural Conf NZ Erg Soc, Auckland, February 1987. New Zealand Ergonomics Society, 1987, pp 157-167. In developing national standards for equipment it is important that the requirements do not limit the design and manufacture process. The author has been involved in developing standards for two pieces of equipment used by disabled people. This paper outlines the main philosophies used and presents a case study of a wheelchair standard.
Environment 19.3.29 (106494)
Goodwin, P.E. Evaluation of methodology for evaluating lighting for offices with VDTs. J Illum Eng Soc, 1987, 16.1, 39-48. Twenty-eight observers evaluated VDT screens under six representative lighting systems. Subsequent evaluation of photographs of the VDTs by these observers revealed a very high and statistically significant correlation between the two methods. These results indicate that this more efficient methodology may be used to examine many important parameters. 19.3.30 (107493)
European Coal and Steel Community Guidelines on the ergonomics of underground illumination in coal mines. ECSC, Community Ergonomics Action, Luxembourg, Report No 9 Series 3, 1987, 49 pp. The guidelines presented in this document are based on ergonomics studies of the lighting requirements in coal mines carried out by member industries of the European Coal and Steel Community. They deal only with the ergonomics considerations covering the relationship between the worker, his task and lighting provision in terms of both safety and performance. They are presented as a practical distillation of current ergonomics knowledge to supplement the specialist engineering skills of lighting and electrical engineers in designing improved lighting installations. The guidelines are presented in two sections: Section 1 covers the general philosophy, objectives and
Applied Ergonomics
September1988
245