Chronology of Published Research.

This Appendix is a selected overview of the wealth of published literature relating to Checkout Safety listed in chronological order of publication. It is intended to illustrate how research in this area developed and to support Chapter 2 of this document.

Pre 1975

Nishiyama, K., Nakaseko, M. and Hosokawa, M. (1973.) Cash Register Operators’ Work and its Hygenical Problems in Supermarkets, Japanese Journal of Industrial Health, Vol.15, pp. 229-243.

This study suggested that workers who had only worked with checkouts for a limited period, experienced health problems. A study of 27 cash register operators implied that most contracted what the authors refer to as ‘shoulder-arm-neck syndrome’ having only worked with checkout for two years.

 

Onishi, N., Nomura, H., Sakai, K., and Yamamoto, T. (1974.) An Experimental Study on the Load Imposed Upon The Arm Muscles In Cash Register Operators, Journal of Science & Labour, Vol.50, No.10, pp.681-710.

Studies were made of three types of cash register. EMG tests were carried out on various muscles including forearm extensors and flexors, deltoid and trapezium muscles. It was found that there was an optimum height for the keyboard of the cash register, at about 55-65% of the height of the standing operator, and that having a keyboard with a tilt of 10° was preferable to that of 30° or 60°.

1975-1979

Nakeseko, M. (1975) Problems of Reducing Work Loads In Cash Register Operation, Comparison of Workloads In Usual Cash Register and Electronic Cash Register Operations. Japanese Journal of Industrial Health, Vol.17, pp.168-169.

Nakeseko investigated the impact that the change from mechanical cash registers to electronic cash registers would have upon operators. The research suggested that newer workstation designs for the electronic registers would provide improved working space, reduce the need for excessive pressure on keys, and not leave the operator as physically drained. However, more operators reported increased drowsiness from the new registers.

 

Hari, T. (1976.) The Health Care For Cash Register Operators of Supermarkets, Journal of Science & Labour, Vol.52, No.10, pp.585-597.

This comparative study identified that supermarket cashiers complained more of neck-shoulder-arm pain and general fatigue than other retail workers. The reports suggested that a change in working hours would have a beneficial effect - since there appeared to be a dose-response type relationship between work and symptom reporting. It was suggested that such a change in working hours was necessary to prevent occupational ill health.

 

Ohara, H., Aoyama, H, Itani, T. (1976.) Health Hazards Among Cash Register Operators and the Effects of Improved Working Conditions, Journal of Human Ergology, Vol. 5, pp. 31-40 (Japan)

The authors report on guidelines issued by the Japanese Ministry of Labour (1973) which were aimed at protecting workers from occupational hazards. A survey of 848 female workers from 13 supermarkets is described. The sample comprises of 339 cash register operators. From the sample, checkout workers reported higher rates of sleeplessness, lower back pain, nausea, and shoulder stiffness than the remainder of the sample which consisted of office machine operators and clerks and other sales personnel.

Reduction of shift times, the use of electronic cash registers and other procedural changes successfully reduced the number of checkout operators with Cervicobrachial disorders. Such changes reduced the incidence of pain in hands, arms, fingers and lower back, however, they did not reduce discomfort in the upper back, neck and shoulders.

 

Maeda, K. (1977.) Occupational Cervicobrachial Disorder and its Causative Factors, Journal of Human Ergology, Vol.6, pp.193-202.

Maeda identified that a high percentage of subjective reports of discomfort from checkout workers could be clinically substantiated, and that complaint rate was linked to clinical severity of the condition. The research suggests that subjective assessment of discomfort by checkout workers could be used, with some reservations, as an accurate measure of health related conditions.

Causation of the condition was suggested to include a combination of high work rates and long work duration with limited voluntary rest periods.

Occupational Cervicobrachial Disorders were considered to be triggered in two main ways: Firstly by the ways workers were using their muscles and nervous system; and secondly by the design of the checking task its self.

 

Aoyama, H., Ohara, H., Oze, Y. and Itani, T. (1979.) Recent Trends in Research on Occupational Cervicobrachial Disorder, Journal of Human Ergology, Vol.8, pp.39-45.

The authors observed that there had been an increase in occupational Cervicobrachial disorders in Japan. The increase was especially pronounced amongst young female workers. Causation of the condition was considered to be:

• Dynamic muscle work from repetitive activities

• Static muscle work - such as raising an arm

• General muscular load resulting from uncomfortable working postures

• such as working at a narrow cash counter

• Mental stress or severe tension

• Environmental factors such as noise

• Poor working conditions

 

1980-1984

Nagira, T., Suzuki, J., Oze, Y., Ohara, H., and Aoyaria, H. (1981.) Cerviobrachial and Low Back Disorders Among School Lunch Workers and Nursery School Teachers In Comparison With Cash Register Operators, Journal of Human Ergology, Vol.10, pp.117-124.

Correlations were found between the individuals work loads and the rates at which complaints were made. It is suggested that the rates of complaints were higher where the work involved localisation of static and repetitive muscle loads and the lack of rest periods. It was determined that the longer the duration of employment the more frequent the complaints of Cervicobrachial disorders.

Koskela, A., Kukkonen, R., and Leskinen, M. (1981.) Symptoms and Clinical Findings in the Neck and Shoulder Region of Checkout Cashiers. Proceedings of the Third Soviet - Finnish Conference of the Results of Co-operation of Work Physiology, Industrial Hygiene and Toxicology.

Cashier work was found to be more mentally demanding than other retail work and that of checkout workers. The work stations were cramped and often cold. Workers sat for long periods of time and commonly reported pain in their shoulders and neck. Symptom reporting was higher than other sales personnel. A group of workers which suffered from what the authors described as tension neck syndrome was identified.

Checkout types were investigated and classified based upon ergonomic principals into good, fair and poor. The researchers found that subjective assessments of the Checkstand design largely coincided with their design suitability predictions.

 

Stresser, H., and Muller-Limmroth, W. (1981) Ergonomics for Check-out Points. How Do We Go About This? Design of Checkpoints With The Human Being In Mind, Bayerisches Staatsministeruim fur Arbeit Und Sozialordnung. Munich, in: HSE Translation No: 11676

This German paper put forward a number of practical suggestions to improve the design of supermarket checkouts based upon scientific studies.

The authors suggested that there were three common checkout types in operation namely:

• Re-pack type system (Trolley to trolley or basket to basket)

• Belt type (trolley to belt to trolley)

• Belt system with compartments (trolley to belt to compartments)

 

Wallersteiner, U. (1981.) Occupational Disorders of Cashier Operators in Supermarkets Human Factors Assoc. of Canada, 14th Annual General Meeting Proceedings pp.79-83

This study looked at how design influenced the well-being of checkout workers in British Columbia. It identified that increases in automation of the checking process had triggered an increase in the number of complaints of discomfort. This small scale study, across two supermarket chains, had only 74 respondents. The study recommended that forward reach should not exceed 40.6 cm, and reported that operators were serving 50-60 customers, handling 420-600 items and filling 50-80 bags each working hour.

Figure 26 Evaluation of working conditions for mechanical cash register (MCR) and electronic cash register (ECR) workers

 

 

Forrester, K., Thorne, C. and Winterton, J. (1984.) Workers’ Investigations Into The Working Environment, Industrial Relations Journal, Vol. 15, Winter, pp.28-37.

This study investigated the impact of new technology upon workers. Making comparisons between the United Kingdom and Sweden the authors proposed that stress would replace many physical workplace hazards, and that employers must proactively monitor the impact which such changes are having on the health of their staff.

 

Wilson, J.R., Grey, S.M. (1984.) Reach Requirements and Job Attitudes at laser-Scanner Checkout Systems, Ergonomics, Vol.27, No.12, pp.1247-1266.

The study looked at the distances which a checkout operator could reach in comfort and compared this to the distances which operators had to reach in order to use the current checkout configurations. Both electronic cash register operators and scanning system users were shown to have a low level of job satisfaction. It was found that workers at laser scanning checkouts experienced a higher rate of discomfort in the neck and arms than workers using electronic cash registers.

 

1985 - 1989.

Buckle, P.W., Stubbs, D.A., and Baty, D. (1986.) Musculoskeletal Disorders (and discomfort) and Associated Work Factors, Ergonomics of Working Postures: Models & Methods, Taylor & Francis, London.

The authors investigated the links between the work activity and self reporting of discomfort. Commonly, back pain was reported but the authors were unable to conclusively identify work elements which could be linked to this. A dose response relationship was found to exist between reporting of foot pain and the time spent standing in the working day.

It is suggested that there is not a linear relationship between time spent standing and discomfort reporting, but that there is a tolerance level which if exceeded, results in dramatically higher discomfort recording incidence.

Source Buckle et. al. (1986)

 

Barnhart, S. and Rosenstock, L. (1987.) Carpal Tunnel Syndrome in Grocery Checkers: a cluster of work related illnesses, Western Journal of Medicine, Vol.147, July, pp37-40

A small cluster of 7 cases of carpal tunnel syndrome amongst grocery workers was investigated. Studies concluded that the cases must be linked to occupation since there was no other identifiable risk factor. The authors suggest that checkout workers may be prone to the condition due to the repetitive nature of their jobs.

 

Margolis, W., Kraus, J.F. (1987a.) The Prevalence of Carpal Tunnel Syndrome Symptoms in Female Supermarket Checkers, Journal of Occupational Medicine, Vol.29, No.12, pp.953-956

This study investigated the high prevalence of self reported carpal tunnel symptoms amongst female checkout operators. The study is based upon a sample of 1,087 useable questionnaires returned by eligible subjects from an initial sample of 1,345 union members. A reporting rate of 62.5% is described. Higher rates of reporting were noted amongst users of laser scanning equipment, and in older employees. A correlation between hours worked and symptom reporting was also noted. The study, however, only investigated ‘reports’ and no medical techniques were employed to verify results.

 

Margolis, W., Kraus, J.F. (1987b.) The Prevalence and Epidemiological Nature of Carpal Tunnel Syndrome Symptoms in Supermarket Checkers, Scandinavian Journal of Work Environment and Health, Vol.13, No.2, pp.165-166

Technological changes were shown to have changed the range of movements of checkout operators. The task was shown to involve repetitive movements of the hands wrists and arms. As an occupation it was associated with a high prevalence of carpal tunnel syndrome. The incidence of the condition increased with the age of the worker. The authors suggested that carpal tunnel syndrome was more common amongst workers using scanning technology, and that reporting of this condition by the workers was higher than their counterparts throughout all worker age groups.

 

Ryan, G.A., Hely, K., O’Brien, G., Young, K and Godfrey, P. (1987.) Musculoskeletal symptoms in supermarket workers. Shop Distributive and Allied Employees Association (Australia) Report.

Based upon 513 responses from supermarket workers in seven supermarkets of varying sizes, this survey investigated the profile of checkout workers and found them to be young (approx. ½ aged less than 20) predominantly female (65%) and with a high turnover (66% of the sample had worked for less than one year with the company).

Checkout workers spent 90% of their time standing and reported significantly higher levels of lower limb, back and upper limb pain that other shop workers. The survey called for checkout work to be re-evaluated and checkout stands redesigned. It argued strongly that standing should be eliminated.

 

Thorne, C., Russell, D. (1987.) On The Till: Workers' Perceptions of Health and Safety in Supermarket Checkout Design, Unpublished, USDAW, Manchester

This paper reviewed the technological changes taking place within the retail industry and described the recent introduction of Electronic Point Of Sale (EPOS) systems.

The paper states that at this time (1987) 95% of all goods which pass through supermarkets are bar coded by their manufacturers and that by 1990 it is anticipated that 75% of the leading UK supermarket chains will be using laser scanning checkouts - making an investment of £200 million over a five year period.

The paper suggests that in a recent survey of checkout workers (USDAW members) all stated that they were dissatisfied with their seating arrangements, 95% suffered with back and neck discomfort and that 50% experienced migraine.

It concludes that the checkout operation has three main problems areas which need further investigation:

• The work itself - weight transferred

• The work environment - noise, draughts & cold

• Job organisation - boredom, interaction with customers

 

Morgenstern, H., Kraus, J., et al (1988.) A Cross-sectional Study of Carpal Tunnel Syndrome in Female Grocery Checkers, American Journal of Epidemiology, Vol.128, No.4, pp.209-218.

This study was undertaken to test the theory that the repetitive tasks undertaken by checkout workers increased the rate of carpal tunnel syndrome. An attempt was made to identify indicators of the syndrome. Using stratified analysis and multiple logistic regression a correlation was shown between reporting of symptoms, age, number of hours worked per week and total years checkout experience.

 

Schmidt, J.K., Gatschall, G.E., Schipani, S.P., and Kysor, K.P. (1988) Do those scanners really make checkers life easy? Annual Proceedings of the Human Factors Conference, Santa Monica California, Vol. 1, pp. 710-713.

The authors noted that whilst the use of scanning systems had eliminated the fatigue caused by locating price tags reading values and typing this information into cash register keyboards, the scanning systems were not without their own problems.

Checkout workers faced physical overload caused by the repetitive need to select, grab, lift, orientate, move and place items. Investigating three different checkout designs, recommendations are made for improvements based upon ergonomic principles.

 

Seidel, B. and Schutte, M. (1988.) Development and First Experimental Use Of A Questionnaire For Ascertaining The Strain During Cash-Work With A Till System in: Contemporary Economics 1988, Edited by E.D.Megan, Taylor & Francis, London. pp.438-443

The study investigated psychological strain upon cashiers using a sample of 162 workers from 11 supermarkets owned by 3 chains. The workers in the study could be subdivided into five categories based upon the checkout system at which they worked and the nature of the store in which they were employed.

The study concluded that mental demands placed upon scanner operators is comparable with those upon electronic cash register operators.

 

Rodrigues, C.C. (1989.) A Technical Analysis of the Supermarket Laser Scanning Workstation in: Advances in Industrial Ergonomics and Safety I (Edited by Anil Mital), Taylor & Francis, pp.953-959.

Rodrigues reported that at this time approximately 50% of the goods sold in the US passes through checkouts using laser scanner technology to read bar codes. The paper suggests that this proportion was rapidly increasing and that the driving force in this change was one of economics.

Rodrigues argues that such changes have placed profitability before workers safety and that the net result was an increase in work related injuries which could be termed "cumulative trauma disorders". The paper looks in some detail at three basic check stand configurations - referred to as ‘Side’, ‘Over-The-End’ and ‘Front’ designs. It evaluates the ergonomic implications of each and concludes that the Front configuration is the more ergonomically sound of the three.

 

Ryan, G.A. (1989.) The Prevalence of Musculoskeletal Symptoms In Supermarket Workers, Ergonomics, Vol.32, No.4, pp.359-371. Taylor & Francis Ltd.,

Ryan surveyed workers at seven supermarkets of varying sizes and concluded from details provided by 705 respondents that checkout workers reported the highest rates of musculoskeletal symptoms of all retail workers, with one third of respondents reporting regular discomfort in some part of the body. Posture and activity was noted at 10 second intervals for periods of 30 minutes compiling a total of 1,000 observations. Analysis showed a significant correlation between the periods of time workers spent standing and the symptoms they reported of lower limb and foot discomfort.

 

1990-1994.

Lannersten, L., Harms-Ringdahl, K. (1990.) Neck and Shoulder Muscle Activity During Work With Different Cash Register Systems, Ergonomics Vol.33, No.1, pp.49-65 Taylor & Francis

Myoelectrical activity measurements were made in the neck and shoulder of eight female supermarket checkout workers. The workers processed 33 items and the results for classic keyboard use, use of vertically mounted scanner, use of flat bed (horizontally mounted) scanners and use of pen readers were all collected and compared.

The study concluded that the work of the cashier caused excessive static neck and shoulder load - irrespective of the checkout system used. It recommended that cashiers be encouraged to alternate between sitting and standing, that they should be given greater guidance on working technique and that their hours should be stringently controlled with regular breaks and changes of working task.

 

 

Marras, W.S., Greenspan, G.J., Schoenmarklin, R.W. (1991.) Quantification of wrist motions during scanning. The Ohio State University Report. The Ohio State University Biodynamics Department of Industrial and System Engineering. Columbus, Ohio 43210

Whist the authors noted that checkout work could have implications for a variety of body areas, the study limited its remit to the wrist. With the participation of four experienced and four inexperienced checkout workers a variety of checkstand configurations were assembled and tested. Operators scanned a standard sample of twelve grocery items using each of the configurations.

The study concluded that no single design was ideal and that at some stage of the scanning operation, wrist acceleration was always above what they considered to be the low risk benchmark for both flexion/extension and radial/ulnar acceleration planes.

Cashier experience, in its self, did not automatically ensure good handling practice, and sound scanning technique.

The report suggested that checkstand configuration - i.e. scanner positioning and orientation were factors which determine the true risk of CTDs in grocery checkout workers. Workstations where the workload could be shared between two hands were considered to be ideal.

Sluchak, T.J. (1991.) Ergonomic Challenges in Supermarket Front-End Workstations Proceedings of the Human Factors Society: 35th Annual Meeting, Vol. 1&2, Chap.321, pp. 862-6.

Sluchak commented that cashiers can handle 500 to 1,000 grocery items per hour - the equivalent of 6,000 pounds of goods in a typical shift, and concisely reviewed a range of published research showing the high reported prevalence of carpal tunnel syndrome and cumulative trauma disorders amongst this population. He concluded that ultimately the physical, repetitive demands on the checkout worker, must be eliminated through checkout redesign.

 

 

Baron, S.L., Habes, D. (1992.) Occupational Musculoskeletal Disorders Among Supermarket Cashiers, Scandinavian Journal of Work Environment and Health, Vol.18, Supplement No.2, pp.127-129 ISSN 0355-3140

119 female cashiers and 55 other female supermarket workers, from 4 stores in a 28 store chain, took part in medical field evaluations. A number of other workers took part in telephone interviews. Based upon logistic regression analysis an association was found between working as a cashier and developing musculoskeletal disorders. Five recommendations are made to improve workstation design - these relate to: positioning of scales; location of the keyboard; positioning of the cash drawer; the provision of a sit stand bar; and making the packing task the responsibility of a second worker.

The design of the checkout they recommend is given in the following diagram, reproduced from their report.

Harber, P., Peña, L.F., Beck, J., Lee, J., and Baker, D. (1992b.) The ergonomics challenge of repetitive motion with varying ergonomic stresses: Characterising supermarket checking work. Journal of Occupational Medicine, Vol. 34, pp. 518-528

The study attempted to quantify the actions associated with checkout work, and to identify a methodology for such studies. 50 workers were each videotaped over three periods of 15 minutes. During this time they handled eight object types which were selected to represent typical grocery objects. Analysing the video evidence, nine types of movement were coded for each of the eight objects. This was repeated 10 times per person.

Measuring: grip; wrist flexion; wrist extension; radial deviation; ulnar deviation; supination; pronation; body flexion; and drag versus lift, results were weighted and an ergonomic risk index created.

The authors concluded that handling certain products presented a significant risk, and suggested that manufacturers should be encouraged to place bar codes differently. They also found that the checkout operators movements were consistent with those which studies had proved posed a significant risk of carpal tunnel syndrome.

 

Hinnen, U., Läubil, T., Guggenbühl, U., Krueger, H. (1992.) Design of Check-Out Systems Including Laser Scanners for Sitting Work Posture, Scandinavian Journal of Work Environment and Health, Vol.18, No.3, pp.186-194, ISSN 0003-6870

The authors studied 46 laser scanner operators and 106 checkout workers who used cash registers. By means of a questionnaire an attempt was made to determine the prevalence of musculoskeletal disorders. Results from the questionnaire were compared with those from a physical examination. Posture analysis and ergonomic checks suggested that a reduced rate of injury could result from improving equipment, re sizing the keyboard, altering the angle of the take off conveyor. The merits of job rotation were also confirmed.

 

Orgel, D.L., Milliron, M.J., Frederick, L.J. (1992.) Musculoskeletal Discomfort in Grocery Express Checkstand Workers, An Ergonomic Intervention Study, Journal of Occupational Medicine, Vol.34, No.8, pp.815-818.

The authors undertook this study in response to employees reports of musculoskeletal discomfort. The report reviews the employers response: the provision of a physical barrier to prevent workers from over reaching; provision of an adjustable keyboard to reduce static shoulder stress; and an education programme to train workers in good posture and good working practices. Such "ergonomic interventions" (pp. 815) were found to have merit.

Workers were judged to be good at identifying and proposing ergonomic solutions. Although following employee advice helped to remove awkward postures and reduce some symptoms, a number of workers still complained of discomfort.

 

Harber, P., Bloswick, D., Luo, J., Beck, J., Greer, D., Peña, L.F. (1993a.) Work-Related Symptoms and Checkstand Configuration: An Experimental Study, American Industrial Hygiene Association Journal, Vol.54, No.7, pp.371-375, ISSN 0002-8894

The authors used a purpose made checkstand, the height of which could be altered (high 33.5" and low 31.5") and which was designed to allow the distance between the end of the conveyor belt and the scanning area to be changed (near 3" and far 9").

42 checkout workers scanned a standardised basket of items with the equipment configured in its high-near, high-far, low-near, and low-far positions. Using ordinal scales operators described their levels of comfort. Counter height and pre-scan area had significant effects on symptom reporting. Symptom reporting was also found to vary with the physical characteristics of the worker.

Higher counters and shorter pre-scan areas were found preferable, however the checkout also needed to have a degree of individual adjustability to ensure that different workers could maintain a good posture.

 

Johansson, A., Johansson, G., Lundqvist, P., Akselsson, K.R., Hansson, G-Å., Persson, L. & Åkesson, I. (1993.) Ergonomic Evaluation of Two Different Locations of the Scales in a Supermarket Checkout System, in Advances in Industrial Ergonomics and Safety V, Edited by R.Nielsen & K.Jorgensen, (from Annual International Industrial Ergonomics & Safety Conference 8-10 Jun'93, Copenhagen, Denmark) Taylor & Francis, London. pp.667-674, ISSN 0-74-840061-3.

The authors undertook a pilot study to investigate the ergonomic implications of positioning the scales used by checkout operators at different positions in the checkout. Positioning the scales to the left (the traditional position) was compared to positioning the scales below the conveyor belt in front of the cashier. This small scale study only involved two subjects, both female cashiers and both with several months experience. One of the subjects was reasonably tall (170 cm) whilst the other was shorter (153 cm). Seventeen items were scanned and a further eight were weighted by the operators in a process that lasted approximately 100 seconds. The operation was video taped and the movements of the workers subsequently analysed in detail.

The authors concluded that the pilot study indicated that placing the scales below the conveyor belt was ergonomically preferable since the handled weights decreased and the working position of the left arm was improved. The improvements were more pronounced for the taller cashier.

 

Grant, K.A., Habes, D.J., Baron, S.L., (1994.) An Ergonomic Evaluation of Cashiers Work Activities at Checker-Unload Workstations, Applied Ergonomics, Vol.25, No.5,pp.310-318. ISSN 0003-6870

This study explores whether standing supermarket checkout workers were exposed to increased levels of biomechanical stress whist working at a ‘checker-unload’ work station where the checkout operator has to remove the goods from the customer trolley and scan them.

The study reviewed the actions of 12 workers from three stores, recording their movements on video tape for subsequent analysis. The results were compared with ones from a previous study involving 10 workers who operated a front facing design of checkout.

The study concluded that extra stresses were placed on cashiers who were required to unload the customers trolley than those who did not, and that checker unload work systems led to increased frequencies of long reach, awkward shoulder positions and more lifting. Recommendations included avoiding checker unload and providing checkouts with conveyor belts for customers to unload goods onto, which would bring the groceries close to the operator. However, if the checker unload system were to be retained it was recommended that the height of the trolley and the height of the checkout work surface should be matched, that the design of the supermarket trolleys be changed to a higher shallower version to prevent workers having to reach down as far, and to locate scales immediately adjacent to the scanner or provide a combined scanner scale to prevent the need for extended reach and lifts during weighing tasks.

 

Lehman, K.R., and Marras, W.S., (1994.) The effects of human interface design on wrist biomechanics during scanning. Proceeding of the Human Factors and Ergonomics Society 38th Annual Meeting. Vol. 1, pp.616-620. Santa Monica, California.

The study looked at the possible impact which improved scanner design could have upon Cumulative Trauma Disorders. The action of 32 checkout workers using 2 window (bi-optic) scanners of four designs were investigated.

The study found that many of the subjects (14 of 32) did not take full advantage of the improved scanning field, and continued to make wrist movements to orientate products which were no longer necessary. Productivity was shown to be higher if both scanning windows were utilised. However the survey concluded that there was a human interface problem using the new technology, and that training would be necessary to ensure that productivity was improved and likelihood of wrist injury reduced using the system.

1995-1997.

Carrasco, C., Coleman, N., and Healey, S. (1995.) Packing Products for Customers: An Ergonomics Evaluation of Three Supermarket Checkouts, Applied Ergonomics, Vol.26, No.2, pp.101-108 Butterworth Heinemann, Elsevier Science Ltd.

This study reviewed three variations of checkouts which required the operator to stand and to pack goods for customers. Musculoskeletal loads and exertion from each design variation were measured. Only five test subjects were used. Each worked for a period of one hour at each of the three checkouts under investigation. The checkouts were in operation in a trading supermarket. Video taped evidence and heart rate readings were studied.

The remit of the investigation was not only to identify possible changes to the design and configuration of the checkstand for worker welfare, but also to produce a specification which improved productivity and used less floor space. The resulting design is shown below.

Source: Carrasco et. al. 1995

 

Marras, W.S., Marklin, R.W., Greenspan, J.J., and Lehman, K.R. (1995) Quantification of Wrist Motions During Scanning, Human Factors, Vol. 37, No.2, pp. 412-423.

This laboratory study was designed to attempt to assess the risk of cumulative trauma disorders (CTDs) amongst grocery scanners. Using experienced and inexperienced workers scanning 12 standard items 19 configurations of checkout were evaluated. The study concluded that it was possible that scanning activities could cause CTDs, however orientation of the scanner to reduce wrist movement, and two handed scanning operations could minimise wrist motions and substantially reduce the risk of injury.

Madigan, E.F., & Lehman, K.R., (1996.) Factors affecting productivity and ergonomics of supermarket checkers. Proceedings of the Human Factors and Ergonomics Society 40th Annual Meeting. Vol. 1, pp.419-423

This investigation revealed that bioptic scanners enabled faster scanning than older flat bed systems. This configuration was shown to require the operator to make fewer wrist movements to orientate products for scanning. The resulting wrist movements were thought to be within the low risk category for upper limb disorders. The manner in which different types of products were handled was also examined and the problems of certain packaging types explored. It was confirmed that product types had an influence on scanning technique. Boxes and bags were commonly handled with lower wrist accelerations. Boxes were typically dragged, whilst bags often had to be flipped. Handling cans and bottles required non-optimal twist motions.