case studies

We have compiled seven examples of how ergonomics has been used to improve the match between people and the things they use and do.

Case Study 1: Computer Operator
Case Study 2: Hospitality and Serving Food
Case Study 3: Lighting at Work
Case Study 4: Wet Mopping
Case Study 5: Shopping Centre, Car Park and Pedestrian Access
Case Study 6: Production Line
Case Study 7: Truck Operators

Case Study 1: Computer Operator

Issue: Frequent user of a personal computer suffers from lower back, neck and right shoulder pain.

Step One: Task Analysis

After further consultation it was established that:

• "Frequent" meant up to 8 hours sitting at the computer per day.
• Software package required use of the mouse nearly as often as the keyboard. Mouse was located on right hand side (RHS) of keyboard.
• Telephone was used regularly. Tendency to cradle handset into the neck when checking information with the computer.
• User had a height adjustable chair and a fixed height desk. Chair had been adjusted to provide a comfortable keying posture.
• As User was relatively short, tended to rest feet on the 5 star base of the chair.

Step Two: Advice

1. Ensure frequent changes of posture occur e.g. stand up, walk around. Avoid sitting for prolonged periods. Frequent short breaks are better than longer breaks taken less often.
2. Train to use the mouse with both hands on the LHS and RHS of the keyboard. In preference, use the "hot keys" on the keyboard as an alternative to frequent use of the mouse.
3. Obtain a telephone headset from the telephone supplier for use on prolonged calls or when interaction is required with the computer.
4. Obtain a foot-rest or equivalent under the desk to stabilise the feet. They should be supported in front of the knee line to enable the back muscles to relax into the chair backrest.
5. Use the backrest angle lever on the chair frequently during the day to suit the activity. For example, when talking on the phone, angle the backrest into a reclined position. Frequent changes of posture are needed to engage a range of muscle groups.
6. Practice some "passive exercises" i.e. gentle stretches of those muscles that feel tired.
7. Relax! Muscle pain can result from feeling stressed and tense. Identify aspects of the job that may cause muscle tension and discuss strategies to address these issues.

Case Study 2: Hospitality and Serving Food

Issue: A large city hotel was being re-furbished and updated. It was thought that the dining room and its equipment could be improved to be both more efficient, and to reduce injury risk to staff.

Step One: Task Analysis

The management and staff were consulted and their main issues noted. The dining room and the staff were observed in busy and quiet times.

Issues and observations included:

• the waiters and waitresses carried large, heavy trays;
• crockery was thick and heavy;
• the sideboard unit where most of the clean crockery and glassware was kept was located at one end of the dining room, with shelves from waist height to floor level; and
• in busy periods staff carried more plates and were quickly and constantly moving between tables and the kitchen and sideboard

Step Two: Advice

The proposed solutions included:

1. reviewing the use of trays and considering using trolleys for some tasks ;
2. changing the tray to a lighter and easier to grasp tray;
3. reviewing the crockery designs and weight;
4. moving the sideboard to a more central location in the room, and modifying or replacing to include some higher shelving, and placing the most frequently used items between thigh and chest height;
5. rostering staff to cope with peak periods; and
6. monitoring changes and adjusting as necessary.

Case Study 3: Lighting at Work

Issue: A company moved into an old building, and the office staff started to complain about a number of issues, including the lighting.

Step One: Task Analysis

After consulting with the manager and the office staff to find out more about their duties and their concerns with the lighting, the general office layout, equipment and tasks were assessed.

Observations included:

• illumination levels at most work areas were well below Australian Standards for the tasks being performed;
• lighting was variable and resulted in an unsatisfactory affect from patchiness and areas of distinct shadow;
• lights were spaced far apart on a high ceiling, and lacked any diffuser system;
• natural light was coming from the eastern windows, and these lacked any window coverings;
• staff having a variety of desks including those with glossy black or white tops - when the white tops had the sunshine directly on them it created reflected glare, and white papers on the black desks also generated an extreme visual contrast;
• most desks being positioned in line with the eastern windows, with the staff sitting with their backs to the windows, or facing the windows. Staff with their backs to the light were working in their own shadow, and often had their computer screens flooded with light and reflecting the sun (facing the windows also made the screen viewing difficult);
• many staff working from documents with a very small font (8 and 9 point) on large spreadsheets, as well as reading handwritten letters and cheques; and
• many data entry staff having the papers and cheques positioned flat on the desks to one side, thus tending to lean and twist when reading the data for entry.

Step Two: Advice

The proposed solutions included:

1. reviewing the existing maintenance and renewal program for the lights and considering the installation of additional lighting where lighting levels were still too low;
2. installing diffusers to reduce the glare and to create a more even light throughout the office;
3. installing window coverings on the eastern windows so that the lighting can be better controlled;
4. re-orienting the desks and/or the monitors, so the main light sources are perpendicular to the desk rather than directly behind or in front;
5. providing document holders to support work (eg. papers and cheques) off the desks and closer to the monitors and the workers’ eyes, encouraging more upright and symmetrical postures;
6. ensuring the monitors and papers are positioned so that the items most often viewed are closest to the middle of the desk, with lesser used items to the sides;
7. providing large monitors for staff who currently have to look at large spreadsheets or other data in very small font size, so font size can be increased; and
8. monitoring the changes to check if any other modifications or adjustments are required.

Case Study 4: Wet Mopping

Issue: Some cleaning staff were reporting back and shoulder pains after mopping the floors in a building.

Step One: Task Analysis

After consulting with the cleaners doing the job and their supervisor, and then looking at the worksite, the equipment, and the cleaners’ techniques, the following points were identified:

Work organisation:

• as a result of roster changes, the two cleaners were allocated a 5 hour block of wet-mopping each Monday;

Environment:

• the trough used to fill and empty the buckets was low but lacked a grate on top, so buckets were lifted in and out of the trough: and
• the main area to be mopped was a very wide, long hallway

Equipment:

• the buckets were the old-style steel buckets, and the wheels were rusty, making them difficult to push along the floor; and
• the mops had long timber handles, extending beyond the head height of these two staff.

Technique:

• the two cleaners both used the same style of twisting and bending to either side to cover a very wide area of floor;
• both had their buckets almost full with water and solution; and
• neither had been trained in safe and efficient wet-mopping.

Step Two: Advice

The proposed solutions included:

1. reviewing the roster to provide a range of tasks each day with different physical demands, in preference to long periods of one task, or tasks with similar demands;
2. installing a grate onto the trough so that the bucket can be slid on and off;
3. installing a hose on the tap so that the bucket need not be lifted for filling;
4. replacing the old, rusty steel buckets with a lighter weight plastic model on wheels;
5. ensuring the equipment suits the user, such that these two cleaners of relatively short stature have the handles cut down to about chin height for a more comfortable and efficient grip;
6. training the cleaners to wet-mop while standing more upright and to use the mop over a narrower width – so for a very wide hall to mop it in two strips rather than one very wide strip; and
7. monitoring the cleaners and the above changes to check if any other modifications or adjustments are required.

Case Study 5: Shopping Centre, Car Park and Pedestrian Access

Issue: A shopping centre was reviewing the safe access for customers from the car park and within the centre itself, being concerned after a few ‘near-miss’ incidents relating to pedestrian safety and slips, trips and falls within the complex.

Step One: Task Analysis

From meeting with centre management and talking to a sample of shopkeepers and delivery drivers, a number of issues were raised. Further assessment required a review of the car park and its use, and customer and shopkeeper movements within the centre.

Observations included:

• poorly marked roadway with few clear pedestrian walkways from the car park to the centre, and lack of lighting and signage;
• walkways that were marked did not lead directly to the entrance, so pedestrians took shortcuts;
• lack of loading dock areas, so small trucks and vans parked illegally in and near pedestrian areas;
• lack of adequate shelter over the complex entrance allowed rain and water to enter and wet the floor;
• lack of suitable absorbent weather matting and some areas had worn and slippery flooring ; and
• food retailers unpackaged products near walkways, some of which created wet/slippery hazards (eg loose grapes, water from iced products).

Step Two: Advice

The proposed solutions included:

1. reviewing all paths between car park and centre to ensure routes lead pedestrians to entrances and have adequate barrier protection;
2. upgrading signage and lighting;
3. improving delivery and loading dock arrangements; by either upgrading and/or adjusting delivery schedules to out of peak times;
4. all tenants reviewing and upgrading their store’s risk management plans with regard to their products, flooring, store layouts and the likelihood of slips, trips and falls within their premises;
5. considering providing umbrella bags on wet days;
6. upgrading flooring in main walkways to reduce slip potential; and
7. monitoring the changes to check if any other modifications or adjustments are required.

Case Study 6: Production Line

Issue: large manufacturing company was re-designing part of the plant to improve the layout and design with the aim of increasing productivity and worker safety and comfort.

Step One: Task Analysis

A meeting was held with management and the line workers to assist in identifying areas of concern, and then the operation of the line and each of the tasks was closely observed.

The findings were:

• a heavy spool had to be manually moved within a large, floor-level cage so that the overhead crane could then lift it onto a machine. As this task was difficult and could only be performed by a limited number of staff (owing to the high physical demands) this stage often delayed the line at least 4 times each day, resulting in ‘down-time’;
• any product being processed in the machine was manually grasped from the conveyor, stacked on the edge of the conveyor, then carried to a plastic bag behind the line;
• some products required very rapid and repeated grasping and stacking, while others had a slower process time, so the worker had to stand and wait;
• workers were standing on a concrete floor throughout the process; and
• once the plastic bag was full, the bag was carried to a scale, weighed, then placed into a bin at floor level to later be lifted and carried to dispatch.

Step Two: Advice

The manual handling could be reduced by:

1. re-orienting the spools so that the crane can pick them up without heavy demands on staff (eg pack the spools in a different configuration or use a cage tilt).
2. either
   • installing a gutter or collecting tray to reduce the need to grasp and tap the product to produce a neat stack; and/or
   • positioning collection bags at the end of the belt, instead of having a collecting area, so that product can be directly fed into the suspended bags;
3. either
   • installing anti-fatigue cushioned matting; and/or
   • providing footwear inserts for cushioning;
4. providing sit/stand seating as appropriate;
5. positioning the scales either
   • near the conveyor; and/or
   • under the collection bags;
6. sliding the product from the scales onto a platform trolley;
7. wheeling the bags to dispatch rather than carrying them; and
8. monitoring the changes and adjust as necessary.

Case Study 7: Truck Operators

Issue: A transport company noticed many drivers reporting chronic neck and shoulder discomfort and some reported wrist pain after operating a particular vehicle.

Step One: Task Analysis

From meeting with management and some drivers, one vehicle and two tasks were identified for further assessment.

The assessment showed:

• drivers sat in a forward-facing seat while they looked out a side window to an operating arm, so they sat in a twisted and side bending posture; and
• the hand furthest from the window (their inside hand) used a joystick and other controls positioned low to the seat, and next to their hip, with the wrist often in a bent, extended posture.

Step Two: Advice

The proposed solutions included:

1. installing additional mirrors so that the truck’s operating arm can be viewed without body twisting at all times;
2. training drivers in the safe use of the mirrors;
3. positioning the joystick and other controls to promote an efficient and comfortable use of the arm and wrist eg with the hand forward of the body, with the wrist in a ‘neutral’ and not a bent posture; and
4. monitoring the changes to check if any other modifications or adjustments are required.