When it comes to office seating, there is no ‘one- size-fits-all’ and there are lots of other important criteria to consider, as Guy Osmond reports.

Manufacturers of workplace seating often talk of products designed to ‘accommodate 90 per cent of the population’. That’s everyone except the smallest five per cent (fifth percentile) and largest five per cent (95th percentile).

This is not as simple as it sounds. A 95th percentile individual is not necessarily made up of 95th percentile body segments and body dimension data tells us that a 50th percentile male may be five inches taller than a 50th percentile woman but is also a little under half an inch narrower across the hips.

In the modern multi-national office, different races complicate the statistics further and, taking lateral dimensions into account, women change shape in different ways from men as their body mass index increases. As obesity becomes more of an issue, specifying a general workplace chair becomes even less straightforward. Many ergonomists believe that the majority of chairs are closer to 60-70 per cent in their accommodation.

So how does a conscientious facilities or health and safety manager ensure best practice? The answer comes in two parts. First, choose your general chair carefully and, secondly, implement a procedure to provide for those who are not properly served by the general chair.

Choosing a general chair will often involve compromise, whether because of budget constraints or corporate sourcing guidelines. We want to minimize compromise and maximize value.

Create a focus group and ensure it contains male and female personnel of different shapes and sizes and, if you have them, ethnic origins. They should also be from different parts of the business with varying job roles.

Make sure you have right- and left-handers and, if possible, include some users with pre-existing physical disabilities and/or musculoskeletal disorders. It’s important to involve your health and safety and occupational health personnel.

Draw up a shopping list of features your chair must include, such as seat slide or adjustable lumbar support. The criteria list should not include any price restriction at this stage. This should be considered later in the process.

Using the shopping list, identify a number of chairs from different manufacturers that all meet your criteria in full (no compromises at this stage). Ensure that all the chairs on your list comply with the appropriate international (EN, ISO) standards. The suppliers should be able to provide this information and explain the relevance of the various standards.

Obtain at least one sample of each chair from your preferred suppliers. Ask the suppliers to demonstrate each chair and explain the features and benefits. This is a good opportunity to judge their knowledge and the likely level of support they will be able to provide in the selection process and subsequent customer service.

Design a score card so that each member of the focus group can rate each chair. As well as comfort, other factors such as ease of adjustment and range of adjustment should be included. You may also wish to score non-physical factors such as environmental considerations and whether the design reflects your corporate brand.

It is often a good idea to weight the scores for different elements. For example, sustainability may be rated out of ten points but the appearance may only be rated out of five points. If you decide to use weighting, make sure you do this before the assessment process begins. If you don’t have the experience or the time to operate such a process, find a good ergonomist to advise you and manage the process.

The foregoing procedure should enable you to create a shortlist of three or four chairs. Now you can introduce price considerations. Doing so will enable you to compare focus group scores with prices and give a more measurable indication of value. Once you have a shortlist, it should be straightforward to select and purchase the best chair for your requirements.

Ergonomics Assessment Software

Non-standard users

You now need a procedure to address the needs of those who find the standard option unsuitable, uncomfortable or inadequate. This may be due to dimensional issues (too big/too small/ too wide/ too narrow), musculoskeletal problems (back or neck issues, upper limb disorders) or because of disabilities (spinal curvature, limb amputation).

To ensure consistency of approach, it is most important to establish a procedure for exception management. If it is not clearly defined and strictly observed, there is a real risk that the exception may start to become the norm or that those who shout loudest (not necessarily the most deserving) get the most attention.

Whilst there will be obvious individuals who will not fit the general chair for dimensional reasons, there will be others with less obvious musculoskeletal or health conditions. The approach should be the same for all of these situations and there are three most likely triggers for exception management: a workstation assessment; a medical report and self-reporting.

A workstation assessment is the most reliable trigger. A computer-based system such as Cardinus Workstation Safety Plus will provide much of the reporting and escalation structure. Where a manual system is used, it is essential to review assessment reports promptly. Employers producing assessments and failing to act on the outcomes are simply creating evidence to be used against themselves in the event of litigation.

Whilst a report from a medical practitioner should be taken seriously, it should be reviewed carefully if the practitioner proposes any physical or product interventions but does not have an occupational health background. Family practitioners, physiotherapists, osteopaths, chiropractors and others have been known to recommend a specific chair model or even a ‘Swiss ball’. However, they are not usually product specialists and any suggestion will almost certainly be simply a personal preference or based on literature they have read.

Self-reporting should be an option available to all but your procedures should always validate the justification for any escalation. It is therefore likely that the initial discussion will lead back to a workstation assessment or medical report before any further escalation is approved.

The individual will now require a one-to-one advanced assessment picking up on the information already acquired. If the source of the escalation includes comprehensive data from the workstation assessment process, the one-to-one may be telephonic. If reliable background, anthropometric and relevant medical information is not available, the one-to-one should be on-site in person.

Assessors must have a good understanding of all the ergonomics and human factors considerations affecting the individual’s work and productivity. The physical considerations will be the most obvious but psycho-social factors will have significant impact so consideration should be given to how much the individual enjoys their job, whether they feel supported by their manager and whether they feel in control of their workload as well as environmental factors such as heat, light, air quality and noise.

Understanding what needs to be done to address these factors is also vital. Competent assessors will have been trained to be fully conversant with the necessary actions and will also have a network of advisors and contacts they can call upon for assistance where the specific requirements of the assessment are beyond their knowledge or experience.

It’s also important to have detailed knowledge of suitable physical and non-physical interventions. Physical interventions will need a substantial knowledge of the various chair manufacturers and models available, as well as the dimensions and features of these chairs and the adaptations available. Research shows that specialist ‘ergo’ suppliers are often the most qualified to provide such knowledge.

At the time of installation, the chair should be installed and set up for the individual with full training provided. The training, which is absolutely crucial to a successful outcome, should explain why the products were supplied, how they will help and how they should be configured and used.

Ergonomic Risk Magazine

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