Posture and workstation ergonomics

Posture and ergonomics for workstations and computers, for back-pain remedy and repetitive strain injury (RSI) and workplace stress reduction

Posture and workstation ergonomics

workplace posture and ergonomics [edit]

posture and ergonomics for workstations and computers, for back-pain remedy and repetitive strain injury (RSI) and workplace stress reduction

Employers have a duty to provide safe working conditions and stress-free work environment for all staff, which includes the provision of information and training for employees about workplace posture and ergonomics. Poor posture at work is a major cause of back pain, workplace stress, repetitive strain injury, resulting in lost time, reduced productivity, poor employee health, low morale, and higher costs. The technical content of this free theory article is provided by ergonomics expert Hugh Babington Smith (now retired), and this contribution is gratefully acknowledged. Applying these simple workplace posture and ergonomics techniques and principles will improve the working environment and well-being of staff.

This material initially clarifies and defines what posture is. It also explains the implications of poor posture, why we should improve posture and the techniques for how doing so. Furthermore the article explains in detail why the employer should take an interest in posture.

UK Government statistics do not show the effects of poor posture in the workplace - the Health and Safety Executive reports instead on absence generally through work-related injury, which includes posture-related causes.

Every employee absence is the culmination of a chain of events. For accidents, that chain may be short. For long term effects of poor posture, the chain is invariably longer. The loss to companies is not just the employees who do take time off because of back pain or posture-related repetitive strain injuries, the loss to organizations is also the reduced efficiency, morale and attitude of those who suffer posture-related discomfort or stress and who 'grin and bear it'.

Although we refer in this article largely to work at computer workstations, the principles apply to any work activity and to our whole life - relaxation, hobby, sport, housework, childcare, in fact any activities which involve the use of our bodies.

 

what is posture?

Posture is a static state - 'A position of the body' or 'An attitude' (dictionary.com), 'Posture is arrested movement' (Bobath). By itself it's a word which is often qualified - defensive, poor, bad, aggressive, happy - and is often used in related ways, with overtones of opinion towards something, sometimes with a meaning of falsehood. What distinguishes it from 'position' is the inclusion of a mental ingredient, particularly mood or emotion; ie., posture is a 'position with attitude', so to speak. We always have a posture of some kind or another, even if the mental intention behind it is subconscious. And, of course, it is well documented that body language plays a large part in communication.

Our bones hold us up, our joints link our bones, our muscles move the bones around the joints and our nerves facilitate control of the whole. The key to good posture is correct joint alignment, but muscle activity, balance and nerves are all part of the picture.

posture - joint alignment

'Joints' are not just the obvious ones such as those on the arms or legs, but the term applies to any links between bones including the spine, shoulders and hips and weight-bearing joints in the feet. There are about 230 mobile and semi-mobile joints in the body. Our bodies evolved for certain purposes and our joints move in particular ways to fulfil those purposes most efficiently. When alignment is 'correct' - that is, in the evolved position - our body is in balance and our muscles and joints are working with least effort.

This actually applies to movement as well as to static posture. Professional athletes go to great lengths to understand this, for then their bodies are not just in balance but achieving maximum output as well. If our joints are used differently from their 'designed' position, we say they are 'out of alignment'. One of the effects of using joints out of alignment is at least discomfort, which can manifest as pain and eventually become injury.

The degree of mal-alignment is material; a very slight amount and the effect is not immediately serious. A greater degree and we know about it instantly. If a joint is both mal-aligned and under stress, something gives and a break or a tear ensues. 'Something gives' can mean quickly or over a period of time if the stress is lower level but repetitive - hence repetitive strain injury. This can occur anywhere in the body.

Malalignment leads to muscle imbalance. Muscles adapt; for instance, an arm in plaster cannot be stretched immediately when the plaster comes off. The same effect happens when a joint is held in the wrong position over a period of time, which is why some people have round backs or slumped shoulders.

posture - muscle activity

There are two kinds of muscle in the body, each with their own function. The first kind, postural or 'slow twitch' muscle, is for holding us in the 'correct' position; these muscles are short and in the deepest layers. The other kind, movement or 'fast twitch' muscles, are for moving us, lie over several joints and are closer to the surface than slow twitch muscles. We need both in varying degrees to perform properly.

Even postural muscles will not hold positions for any length of time if they are not used regularly, a good reason in itself for sedentary workers to take exercise and understand alignment. Slow-twitch fibres determine endurance, whereas quick-twitch fibres determine muscle power. The phrase 'muscle tone' in physiotherapy refers to the amount of fibres in the muscle 'firing' at any one time. Even at rest, some fibres are firing and the muscle is 'ready to go'. Only when a body is dead is there no muscle tone. The amount of muscle tone in a posture is largely a function of the amount of support being provided. At an extreme, a person lying on their back has a wide support base, so minimum muscle tone. At the other extreme, a person standing on tiptoes on one leg has a very narrow base and so needs maximum muscle tone in perfect alignment. The muscles are, of course, governed by the brain: lift an empty box that you believe to be full, and it shoots up into the air as your brain orders too many muscle fibres to fire for the task.

posture - balance

A contributory factor to holding a posture is balance. Balance can be used in two ways when talking about posture. It can mean the balance of opposing forces - for instance, are the muscles holding the shoulders back strong enough in comparison with those pulling the shoulders forward? If not, the result is a round back. Secondly, it can mean balance in the sense that if it is not right, the person falls over.

A person with good muscle balance will be able to hold an unstable position for longer because they recruit the postural muscles in the correct alignment and their movement muscles are less involved. A person with poor balance will move a lot and have to use the movement muscles to try to get back to balance. These muscles will get tired quickly and the correct posture will be lost.

posture - nerves

We control our movement through our nerves. Messages are passed in both directions between the brain to and from the extremities, the muscles and the joints. If this passage of information is disturbed, we cannot have proper movement. Nerves are physical entities and just as subject to maltreatment as bones and muscle; they can be affected by blows, by stretching, by pressure, by twisting. They pass between muscles, along bones and joints on paths developed, like the rest of the system, during evolution. So again it follows that if alignment is not right, the nerves may be affected.

poor posture effects

What happens if posture is poor? In each of the areas of joints, muscles and nerves there can be effects of mal-alignment. These ill effects may start out as very slight, they may remain at a very low level, but if the cause does not disappear, they will get worse and may become intolerable.

Mal-aligned joints and ligaments may just feel uncomfortable, may ache, or hurt. Shear forces (that is, across rather than along) the spine may affect the discs, putting pressure on the nerves that fan out from the spine.

Muscles will suffer through lack of circulation, which may manifest itself as discomfort, ache or pain as well as lack of performance, getting tired quickly. The body's healing process is impeded when blood-flow is restricted.

Pain may arise when nerves are stretched or inflamed by mal-alignment. Again, the range of symptoms may be from discomfort, through tingling, pins and needles, hot or cold feeling or numbness to pain. A characteristic of nerve damage is that sometimes the symptom is not in the place where the damage is being caused. For instance, a nerve being damaged in the lower back may cause tingling in the thigh or pain around the ankle.

poor posture causes

Why do we have poor posture? There are two sides to this, physical and mental. Physically, the short answer, going right back to fundamentals, is that we are hunter-gatherers, with our roots on the savannah, evolved to spend our days wandering in search of berries or pursuit of prey. We no longer do what we evolved to do. We are emphatically not designed to spend our day sitting on our bottoms staring fixedly at a computer screen or in a car seat staring at the road ahead, or for any of the other activities of our modern life that are so far from our origins.

Mentally, we have unnatural pressures that bear on us all the time. No doubt the link between posture and attitude derives from relationships within our hunter-gatherer community - authority, submission, joy, sadness and so on - but today life is complicated by the sheer variety and duration of circumstances and information that affect us. Thus a person with an oversized mortgage, an unpleasant commute and an unhappy job will tend to have a worn-out demeanour with the posture to show it: round shoulders and a curved spine.

posture discomfort and pain - remedial actions

What can we do to relieve discomfort and pain? There are three main steps:

  1. understand that you can take control
  2. listen to the body
  3. take action
1 - take control

Mind and body are closely linked. In many instances we are, without realising it, in control of the conditions that give rise to pain and are therefore in a position to get rid of it. Once we understand this and consciously take control, we can achieve quite remarkable advances and be very much happier.

It's as much a mental as a physical approach. We know a happy person when we see one - we talk of 'a spring in their step, head up, chest out.' We know instinctively what such a posture means.

Our brain controls our posture through the nerves. Our mind can control our brain One way of implementing that control is to alter our posture positively. Try walking with a spring in your step, add in a little skip, your head up and chest out - you will probably feel a lift and may well have a smile on your face at the same time. That is the first step. Think positively about improving your physical posture.

Very relevant to this is the work by Professor Michael Marmot, Professor of Epidemiology and Public Health at University College, London. He believes that "The reason that low status may translate into poorer health is lack of control and fewer opportunities for full social engagement or participation." (newscientist.com).

There is no reason for anyone to be in 'victim mode', feeling that the world has it in for them, that there is nothing they can do. As many practitioners will tell you, if you cannot bring a person to believe that they can do something for themselves and get them to exercise some initiative, you cannot begin to change their pain. Once they have decided to change, the results can be remarkable.

When people understand why and how to take control, their health improves.

2- listen to the body

The second step is to listen to the body. Why do people 'grin and bear it'? Because they are not listening. Discomfort and pain are telling you something. In particular, with musculo-skeletal matters, the pain and discomfort are telling you that something is not right, something is out of alignment, or something is moving in an incorrect way. Analyse the feeling, look for the root cause and seek ways of changing.

Pain is subjective. There are many cases of people with quite severe injuries that they hardly notice, whilst other people with injuries in the same area but to a lesser degree may be in agony. It is noticeable that when a person is concentrating, they may even temporarily put themselves in the position of not feeling the pain. Indeed, it can take a very long time for the body to 'get through' to the mind and make the point that something is not right. Unfortunately, all this time the damage is getting worse. So it is worth treating the messages of discomfort and pain positively, by listening to them.

3 - take action

The third step is taking action. There is nothing to be gained from inaction, from grinning and bearing it.

The best action is prevention. Not the lazy form of prevention, expecting ergonomic equipment on its own to solve the problem - anyone can habitually slump in even the best chair in the world. The principles and outlines of human bio-mechanics combined with movement training and exercises are an effective and long-lasting form of prevention, requiring a degree of application.

Even if we are not in direct control of our discomfort - for instance, our equipment is ill-designed - we are usually in a position to talk to someone who is in charge so that something can be done. In the workplace, we have a legal duty to report problems whilst the employer has a duty of care towards the employee.

In particular, it is essential that if you have tingling, pins or needles, numbness or discomfort in the fingers, wrists and/or hands, ask for expert medical opinion to be sought immediately. It is not enough to rely on the opinion of someone who does not have this training.

Even some general practitioners/doctors do not yet recognise the importance of immediate intervention. A recommended first point of contact in the UK is a member of the Association of Chartered Physiotherapists in Occupational Health and Ergonomics (ACPOHE).

In other cases a solution may be easy; many people do play around with their circumstances and find that a change removes the pain. Unwittingly, they have achieved the right result. Sometimes people may not be so perceptive or their circumstances are more complicated and they might need some postural re-education. To change posture is a more mental than physical challenge. We all have our own posture ingrained in our brains as being 'correct' either by habit or by upbringing. However, in cases in which posture is in fact incorrect, the brain needs to be re-programmed to accept the correct messages; training with constant reminders and repetitions in the early stages is required. This need not be particularly time consuming. Complete postural re-education for people who have problems should, with weekly professional help, take no more than 4-6 weeks; the effects can last a lifetime.

good posture at work is important to employers

Providing education, advice and training about workplace posture is an integral part of maximising the investment in employees. Employers now have to invest huge amounts of management time to comply with employment and health and safety legal requirements. Many of these are designed to deal with negative circumstances that arise - ie., they are reactive; investing in prevention is an excellent way of minimising management time overheads.

In many businesses employees are the most expensive asset. It makes sense to ensure that this asset can work most efficiently. Therefore something that is fundamental to the individual is fundamental to the employer as well. Modern life is bad for posture and the chances are that any new employee may have musculo-skeletal problems. If this is tackled at its roots, management time is saved; each employee be giving better value for money, and the employer achieves an advantage over its competitors who fail to act in this area. Enabling a positive approach to posture is a serious competitive advantage.

good posture and the individual at work

Readers may recognise this posture model and diagram, adapted from the Frederick Herzberg's motivation theory. The maintenance or hygiene factors in blue are those which are obviously affected by poor posture.

Home life will be affected if a person is in pain - sometimes to horrendous degrees, a vicious spiral downwards that can end in the divorce courts.

In the workplace, many employers believe that nothing is wrong because no one has complained. In fact, because people suffer in silence - the 'grin and bear it' effect - they are not working to full efficiency. Unless something gives and the employee speaks out or takes time off, the employer simply does not realise that the salary bill he is paying is not bringing the value for money or performance expected.

Relationships suffer from an individual's poor posture. It is hard to be polite or friendly when you are in pain, especially if you think that there is nothing you can do. Supervisors will manage less effectively; colleagues will be harder to bear; subordinates will be less cooperative.

employers benefit from investing in workplace posture and ergonomics

How do organizations benefit from investing in posture? Workplace posture is very important to employers. There are three main areas of business life in which the employer will gain from investing in improving posture at the workplace:

  1. greater efficiency through improved morale, higher productivity, and less absenteeism
  2. compliance with health and safety law
  3. reduction of the risks litigation from injured or stressed employees
1 - posture improvement effects on employees' efficiency and absenteeism

For many years, official international statistics and reports about workplace illness have listed musculo-skeletal disorders (MSDs) as the biggest cause of workplace illness and absence, within which, backpain is substantially the largest element.

For example, this extract from a 2007 report by the European Agency for Safety and Health at Work: "Musculoskeletal disorders (MSDs) are the most common work-related health problem in Europe, affecting millions of workers. Across the EU27, 25% of workers complain of backache and 23% report muscular pains. MSDs are caused mainly by manual handling, heavy physical work, awkward and static postures, repetition of movements and vibration. The risk of MSDs can increase with the pace of work, low job satisfaction, high job demands, job stress and working in cold environments. MSDs are the biggest cause of absence from work in practically all Member States. In some states, MSDs account for 40% of the costs of workers' compensation, and cause a reduction of up to 1.6% in the gross domestic product (GDP) of the country itself. MSDs reduce companies' profitability and add to the social costs of governments."

These reports are broadly consistent with earlier UK figures and indicate a long-standing trend, for example in 2001/02 about 10 million days were lost through work-related musculo-skeletal absence, with an average absence of about 20 days per case per year. Over the same period there were c.28 million people in employment, so the lost days amounted to 0.2% of the days available for work. The days lost involved just over 2.2 people per 100. To reiterate the point made in the introduction, these statistics do not show that the real loss to companies. The full loss is not just the work-related absenteeism, it is also the inefficiency of those who 'grin and bear' their discomfort, and the inevitable negative effects on productivity and quality due to absence and illness-related work disruption.

During the period (often weeks and months) before time is taken off work because of pain, a person will be working with ever-decreasing efficiency. Results (August 2004 - from the author's work) from a sample of about 200 people in several companies show that 70% of people in offices suffered musculo-skeletal problems. About one third of all respondents had low level discomfort, but nearly one fifth of people report 'moderate' pain. It is the latter who also reported reduced efficiency. This reduction in effectiveness means that, on average, for every 100 people being paid an employer is probably achieving 94 employees' worth of work. Leaving these employees to suffer in silence has a price. Taking measures to reduce pain and discomfort due to poor posture is often a significant opportunity to increase efficiency, morale and working conditions, requiring much lower investment compared to many other performance initiatives.

2 - health and safety legislation (uk) relating to workplace posture

Most computer users are by law subject to the display screen equipment work-station risk assessment regulations. Don't let the sheer length of the title of the relevant regulation deter you - this is important employment law in the UK, and will have equivalent provisions in many other parts of the world:

  • Health and Safety (Display Screen Equipment) Regulations 1992 as amended by the Health and Safety (Miscellaneous Amendments) Regulations 2002

Also refer to the raft of related legislation, notably:

  • Health and Safety at Work etc Act 1974
  • Management of Health and Safety at Work Regulations 1999
  • Workplace (Health, Safety and Welfare) Regulations 1992 (as amended)
  • Provision and Use of Work Equipment Regulations 1998 (as amended)

The Display Screen Equipment Regulations mentioned above not only require employers to carry out assessments, but also that users are 'provided with adequate health and safety training in the use of any workstation upon which he may be required to work'.

The UK HSE guidance on the regulations (ISBN 0-7176-2582-6) suggests a six-step approach to this training including

  1. user awareness in correct and timely detection and recognition of hazards and risks
  2. simple explanation of causes of risk mechanisms of harm (i.e. poor posture)
  3. user-initiated actions to bring risks under control including training on posture
  4. arrangements for bringing problems out into the open and doing something
  5. information about the regulations to be given to users, and
  6. the user's duties.

Throughout the regulations there is mention of the importance of users taking control (generally a principle in effective health and safety policy) and of the importance of good posture. It is understanding of good posture that seems often to prove a sticking point in effective implementation of the regulations and is one of the reasons for this article being written. Without good posture, the best assessment in the world will not prevent discomfort, pain and injury. So a fundamental element in actually complying with regulations is the effective and knowledgeable training in posture.

3 - reduction of litigation risks

In this age of increasing litigation - the modern blame culture - there are most certainly risks for employers in allowing people to suffer from posture-related musculo-skeletal problems. Even though risk of legal action and prosecution is currently relatively low, the costs to employers of finding themselves on the wrong end of a claim for damages can be so high that it is worth reducing all risks as far as possible, especially as there are positive benefits as well from such investment. Employers that are able to demonstrate adequate steps have been taken to prevent and avoid posture-related problems and injuries will most easily be able to defend any claims that do arise.

The technical information in this article was kindly provided by workplace ergonomics expert Hugh Babington Smith (now retired, prior to which he ran the UK company Etcom People Engineers) and this contribution is gratefully acknowledged.



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authorship/referencing

© technical content hugh babington smith; contextual material, edit, code etc alan chapman 1995-2014