Ergonomic design of packing stations

Logistics is a sector that places high demands on its workers with heavy loads being carried, pulled, lifted, picked and packed. Standing for long periods is also common. These demands exert a high physical strain on a worker, which can be accentuated in the logistics sector due to the addition of time pressures – particularly in e-commerce environments. An increasing requirement for faster operations intensifies pressure on workers, who risk quickly reaching their physical limits.  

Poor ergonomics in the workplace can lead to a variety of health issues, driving a subsequent increase in employee absenteeism. Common ailments include neck, shoulder, back and lower back pain, digestive problems, aching legs, heart and circulatory problems, low cerebral blood circulation, visual disturbances, sciatica, various back problems. 

Manual handling, awkward or tiring positions and keyboard work or repetitive action are estimated to be the main causes of work-related Musculoskeletal disorders (MSDs), based on Labour Force Survey (LFS) data (1). 

According to the Health and Safety Executive (HSE) (2), MSDs mainly comprise work related upper limb disorders (WRULDs) and back injuries. WRULDs are chronic (persistent) injuries such as tenosynovitis and carpal tunnel syndrome and result from repetitive tasks. Chronic back pain can result from repetitive or awkward lifting, which is often a risk on packing lines in logistics operations.  

In fact, MSDs relating to spine and back problems are common in production and warehouse operations, where potential causes of adverse strain leading include overhead work, regular bending, activities with a bent upper body and the permanent sitting posture at the desk. Wear and tear on joints, vertebrae and intervertebral discs are typical consequences. Psychological factors, such as stress, can also contribute to backache symptoms.  

HSE’s Working Days lost in Great Britain statistics for 2019/20 (3) show that stress, depression or anxiety and MSDs accounted for the majority of days lost due to work-related ill health, 17.9 million and 8.9 million respectively. On average, each person suffering took around 17.6 days off work. This varies as follows: 

• 9.1 days for Injuries 

• 20.0 days for Ill health cases 

• 21.6 days for Stress, depression or anxiety 

• 18.4 days for Musculoskeletal disorders 

All of this highlights why ergonomic design is vital for workplaces in warehouse and logistics operations. 

Ergonomics – the term derived from the Greek words for ‘work’ (ergon) and ‘law’ (nomos) – aims to optimally adapt the workplace and environment to the individual.  

According to the HSE Brief Guide: Ergonomics and human factors at work (4), ergonomics – known in some industries as ‘human factors’ – is a “science concerned with the ‘fit’ between people and their work. It puts people first, taking account of their capabilities and limitations. Ergonomics aims to make sure that tasks, equipment, information and environment fit each worker.” 

The Guide goes on to point out that ergonomics can “reduce the potential for ill health at work, such as aches, pains and damage to the wrists, shoulders and back”. It adds “if you don’t follow ergonomics principles, there may be serious consequences for people and whole organisations. Many well-known accidents might have been prevented if ergonomics and human factors had been considered in designing people’s jobs and the systems they worked in.”  

According to the HSE in the UK, employers must protect the health and safety of their workers and other people who might be affected by what they do, under the Health and Safety at Work etc Act.  

The Management of Health and Safety at Work Regulations require employers to assess the risks to the health and safety of their workers. The assessment may identify risks covered by other regulations relevant to MSDs in the workplace and you should also comply with those regulations. The main ones are listed below. Other laws may also apply within specific industries.  

The Manual Handling Operations Regulations require employers to carry out a risk assessment on all manual handling tasks that pose an injury risk. Employers must: 

• avoid hazardous manual handling, so far as is reasonably practicable 

• assess the risk of injury from any hazardous manual handling operations that cannot be avoided 

• reduce the risk of injury from hazardous manual handling to as low as reasonably practicable. 

The Health and Safety (Display Screen Equipment) Regulations set out what employers should do if their workers are habitual users of display screen equipment, including:  

• perform a DSE workstation assessment 

• reduce risks, including making sure workers take breaks from DSE work or do something different 

• provide an eye test if a worker asks for one  

• provide training and information for workers. 

The Control of Vibration at Work Regulations require employers to protect workers against risk from exposure to vibration at work. Powered hand-held tools, for example, can cause hand-arm vibration syndrome (HAVS).  

The Workplace (Health, Safety and Welfare) Regulations cover a wide range of basic health, safety and welfare issues, including lighting, floors, workstations and seating. They apply to most workplaces. 

Workers also have duties under the Health and Safety at Work etc Act. They must take reasonable care of their own health and safety and that of others affected by their work. They must also co-operate with their employer so they can comply with their health and safety duties. 

In addition, the Management of Health and Safety at Work Regulations require workers to make use of equipment their employer has provided for them, in accordance with their training and the instructions their employer has given them. 

Occupational science makes a distinction between stress and strain. Stresses can be determined objectively and are divided into physical, mental and psychosocial. They can be influenced by personal factors, individual conditions and external factors (such as scope of activity, action and decision-making) impacting on the employees. By understanding what causes stress, it is possible to modify any stressful factors. Ergonomic design of a work environment must therefore, always take into account subjective effects on the respective employee, in addition to objective criteria. 

 

For packers working at packing stations there are a variety of physical, mental and psychosocial stresses that can occur, including: 

• Handling heavy and bulky products for packing 

• Lifting and lowering movements, also partly with body rotations, are regularly performed 

• Packing items over the flap of erected folding boxes or containers can be awkward 

• Packers will need to chose from a wide range of void fill material to secure the goods in the carton and prepare the packages for shipment 

• Placing units on pallets or conveyor belts will cause physical strain 

• Complex accounting procedures on the computer must be completed 

• Existing dust as well as noise, etc. generally makes the work more difficult 

• Insufficient staff to handle the packing volumes. 

An ergonomically designed, electrically height-adjustable packing table will allow a packer to optimally adjust it to his or her own height and according to the goods being packed. A scale embedded in the work surface of the packing table will be linked to the warehouse management software. Above the scale, where the actual packing process takes place, there will be a dispenser for packaging aids and filler material. If required, this will drop directly into the packaging. Slightly offset, next to the scales, will be a computer screen mounted at viewing height with a keyboard located on a sturdy swivel board beneath. Next to it will be a printer for shipping papers, which is placed on a low-slung extension to account for the printer height. The packaging materials and cartons are vertically positioned above the work surface and can be gripped without turning the body. Directly next to the tabletop with the scales is a continuous conveyor, onto which completed packages can be transferred by means of a flexible plate. This avoids lifting and pushing movements for the packer. Similarly, depending on the packaging process, a lifting table ensures that the packer does not have to bend or stretch excessively when loading the package onto a pallet or roller container. Manipulators can be provided for lifting and lowering larger loads. If possible, standing or sitting workplaces should be offered. Such a design avoids unnecessary lifting and lowering of loads and it will prevent bending, stretching and body twisting with weights. 

Packing tables must always be individually designed. There must be sufficient storage space for a day's supply of materials such as tape and paper, as well as structured storage areas and waste disposal facilities. The working environment should be bright, clean and dust-free. The tools for carrying out the work task should be within easy reach and always available at the same places in the work area. A clear structure and order avoids search efforts and errors and generally facilitates the work. The computer screen at the packing table must display sharp and high-contrast information and the input screens should be simple and appealing. 

An ergonomic packing workplace design as described above will allow packers to work more intensively and with less strain. They will be more focused, less fatigued – thus reducing the susceptibility to errors.  

A packing station must always be examined and configured on a case-by-case basis. The solution will take into account existing requirements of orders, the products being packed, integration into other warehouse processes and the employees involved.

Literature:

1. Labour Force Survey (LFS) run by Office for National Statistics (ONS) https://www.hse.gov.uk/statistics/lfs/about.htm 

2. HSE Guidance Musculoskeletal disorders https://www.hse.gov.uk/food/musculoskeletal.htm 

3. HSE Working Days Lost in Great Britain Statistics 2019/20 https://www.hse.gov.uk/statistics/dayslost.htm 

4. HSE Brief Guide: Ergonomics and human factors at work. https://www.hse.gov.uk/pubns/indg90.pdf