Michael Patkin's

Occupational strains in school-children
- do they exist?

Publication history, Reflections & comments



Surgery & ergonomics


Information design

Editorials, book reviews





Pains in children share important attributes with occupational pains in adults. The many strands are hard to disentangle, but they should be clearer with careful analysis, attempted in this paper. Some problems arise from the complexity of the conditions concerned, and others from the bias of the observer.

There are instances of children injuring themselves from sustained repetitive activities, such as the hula-hoop syndrome, Rubik cuber's thumb, and guitar nibble, but they are extremely rare. It only takes an isolated case report, or perhaps a dozen of them from some busy highly specialised clinic overseas, for newspaper reports to imply an epidemic.

There are also less rare conditions, such as surfers' knees. Poor posture is common, but its criteria and significance are hard to decide on. Tense handwriting technique is the general rule, and its significance is more obvious and discussed later in detail.
Health problems related to children's activities are often psychological. Examples are stomach pains at school camps, and epidemics of over-breathing at pop concerts. Children follow fads quickly, ranging from games like yo-yo to fashions like long hair. Their beliefs are equally volatile, which makes them vulnerable to damage from misleading advice about imaginary hazards.

Today there is understandable concern among teachers of computing and business subjects such as typing. Many of them worry about whether their students are at the same risk as adults of problems of neck and arm pain, of the kind found in epidemic numbers in adult key-board workers in some government departments and other organisations. This paper aims to show that the likely problems are minor ones, unless they are inflated by misplaced concern, but that there are some unexpected aspects of schooling which cause problems in adult life.

The problem in adults

Occupational injuries are a matter of major concern to the community, and especially to trade unions. Anyone who has seen patients with amputations from heavy industry, or burns, or has seen the pathetic shortness of breath of a victim of terminal lung disease, is committed to ensuring safety and health at work.

Public concern in this area has been heightened enormously through union activity. In 1981, the Australian Council of Trade Unions created an Occupational Health and Safety Unit, which was effective in starting to catch up with decades of neglect in this area.

Back injuries are the commonest safety problem in Australian industry. These cause more controversy than the injuries already mentioned. Objective evidence for injury is less evident, and a small proportion of claims are fraudulent. There is a much larger grey area of "discretionary effort", where the compensation system rewards incapacity, and arguments about it continue to rage.

The present epidemic of neck and forearm problems in keyboard workers is largely a replay of the bad back epidemic of the 1960's and 70's, with all its mistakes. One difference is that surgeons have learned not to try to effect a cure by operation except in a few cases. The other is the huge publicity that has been given to occupational strains with the misleading and damaging label pronounced Are-Ess-Eye. We will return to this label later.

From 1981, an alarming rise in the incidence of reported arm and neck strains occurred in factory workers in New South Wales (Ross, 1985). This was followed by a more spectacular rise in similar problems in white-collar areas, especially clerical work in government departments. At first this was related to keyboard work. Now, in 1986, discussion with union industrial officers indicated that the main problem is not typing or data entry, but in jobs where handwriting is a large part of the work.

The early reaction of some doctors to this epidemic was to apply labels like migrant arm, malingering, and compensation neurosis, repeating the mistakes made in dealing with back injuries. Doubtless a few cases came into this category, but insulting the majority of cases led to a reaction. Despite the obvious psychological components in some cases right from the start, and which increased with time, there were dogmatic claims of an injury to the tissues in every case, an equally extravagant proposition which hardened attitudes on both sides of the argument. The whole present phenomenon can be summed up by saying that it is 20 per cent bad ergonomics, 30 per cent medical muddle, and 50 per cent bad management practices and industrial relations.

A selective classification of common occupational strains

Many hundreds of different occupational strains have now been recorded (Hunter, 1965). Among the ones important for the present purpose are several dozen labels applied to currently prevailing conditions of occupational pain and strain. They are hard to classify, because some are labelled by cause, some by effect, and some by their main associated factor. Further, the nature of causes and effects are far from clear and agreed on. Nevertheless they can be put into several main groups:

1. Anatomically and pathologically well-defined conditions like trigger finger, lateral epicondylitis, and subacromial bursitis.
2. Less clear-cut local conditions of tissue, such as tendinitis, and "pinched nerves in the neck", where the postulated abnormalities in the tissues to which pain is localised are controversial.
3. More controversial conditions of tissue, injury or change, where assessment and interpretation is even more contentious. These include myalgia, primary fibromyalgia. regional pain syndrome, myofascial pain syndromes, and psychogenic rheumatism.
4. Chronic pain syndromes, where the origin of the symptoms is no longer in the tissues of the arm or the neck, but is perpetuated by abnormal activities or subtle changes in the brain, or the mind. (The problems of mind-body dualism highlighted by Descartes centuries ago can hardly be solved by brief, silly, dogmatic statements today).
5. Particular occupations or activities, for example playing the clarinet or making part of a shoe on an assembly line.
6. Bad ergonomics, excessive workloads, the perception of stress.
7. Psychological, cultural, and social factors among employees and workers.
8. Deception.

Anything you say about Are-Ess-Eye is five per cent correct. Any one person has several factors contributing to their individual problem and each different element has its own treatment. Up till now, the general rule has been to make a blanket diagnosis, which smothers not only accurate diagnosis but treatment which is appropriate, and effective prevention.

The first variety of occupational strain and pain which came to public attention was "tenosynovitis", found in some factory workers. This is a clear-cut medical condition, with a definite set of symptoms and clinical signs. These include indisputable and persistent swelling, and creaking on movement, readily felt with the fingers or heard with a stethoscope. Unfortunately the label of tenosynovitis was quickly applied to the problems of keyboard workers, in whom it is rare. It was common in headlines, articles, and arguments, and even to naming support groups ("The Tenosynovitis Association"). As reaction has grown to the abuse of inaccurate labels, the terms now being used are over-use injury, or syndrome.

The are-ess-eye label

The three-letter label misled workers and managers into looking only for a mechanical fix and altered work loads. A common complaint two years ago in Australia (on talk-back radio for example) was "we/they bought the ergonomic furniture and we still have problems".

To use the "Are-Ess-Eye" label is like applying the same diagnosis of "colic" to symptoms caused by gall-stones, duodenum ulcer, a ureteric calculus, or irritable bowel. In each case, removing the appendix is likely to give some relief because they are episodic conditions. Having waxed, they may wane for a short time, and the benefit is put down to appendicectomy, wrongly. The trouble will return, and worsen. In the past, this very operation was done at times for repeated attacks of abdominal pain in children. Occasionally the results were good (for good reasons, too detailed to discuss here). Often the results were bad, because the problem was a school phobia, or parental tension, or lack of roughage due to hurried breakfasts, or threadworms.

There are more reasons for avoiding the Are-Ess-Eye label. One is that many human propositions fulfil themselves through their expectations. An example which industrial psychologists are familiar with is the Hawthorne effect. Briefly, it was found that factory output went up whether experimental rest pauses were frequent or not. The factor was the personal interest taken in the workers. The same effect was found when light-bulbs at work were replaced with others of the same power. Productivity went up because people thought the lighting level had been increased.

The problem in children

Children are much more susceptible to influences than adults. They grow up in the religion of their parents, which might be quite an unusual one, or rebel against it because of other influences. They develop many different fads in clothing, food, and games.

The unconscious beliefs of those who influence them may be powerful agents. The Pygmalion effect (Bocock, 1978) is a term applied to a situation where a teacher has been told that one half of a class of children are brighter than the other. After a few months, this group scores better on examination than the allegedly duller half of the class, even though the labelling had been done quite at random. The children fulfilled the teacher's expectations.

A similar phenomenon occurred with the label of hyperactivity in the United Sates several years ago. This became so common a label that there were classrooms where it seemed many children ought to be on some kind of drug treatment to control the problem. Then it faded away.

It seems likely, from these analogies, that some children will develop pain from an activity such as typing if that is what they are told to expect. This is especially so if they happen to have temporary discomfort for some other reason. One such condition is the ill-defined but common problem known as "growing pains". In this, a child complains of limb pains for which no physical cause can be found. Whatever its basis, there is no need to restrict activity or treat in any way other than reassurance.

It is predictable that uncommon and serious condition such as osteomyelitis or bone cancer are sometimes given the same label in their early stages. This could only be avoided if all children with limb pain, and their parents, were given the same grim reservations about what is generally a trivial
condition. The effect would be anxiety or panic, and restriction of activity. In adult literature on occupational pain, it is common to see warnings of the dangers of Are-EssEye from excessive typing. This is the same literature which some children are now reading. "latrogenic" describes disease caused, rather than cured by doctors. These newer disabilities could be equally unfortunate.
Today there are school curricula which recommend study of Are-Ess-Eye. Children are asked to prepare assignments which are based in part on scare literature about the crippling effects of tenosynovitis, (a specific condition which is not relevant to typists) and on other unproven or misleading material, such as advertisements for wrist rests and kneeling chairs, and the effects of fluoride in causing the condition.
Ill-informed or misguided teachers are in a powerful position to do great harm.

Behavioural contagion is well- established as a phenomenon in adolescent females. A classic study in social psychology, "The June Bug" (Kerchkoff, 1968), described an epidemic of what looked like insect bites in a clothing factory, for which the most
painstaking investigation could not find a cause. Lofland (1981) has reviewed epidemics of physical symptoms with psychological origin, and found that those affected are typically those who must perform under great pressure, have poor relations with supervisors, and little opportunity of effecting change.

Clinical psychologists are familiar with attacks of fainting and abdominal pain spreading through a school, affecting adolescent girls - the very age of those who would be studying computing in years 11 and 12. Teachers confronted with such problems are most successful if they do not get panicky, but react with slight boredom to the whole problem. Aldous Huxley, in "The Devils of London", described a similar phenomenon in the seventeenth century in nuns, who fantasized that they had been possess by devils, developing paroxysms of obscene and hysterical frenzies.

Other views

A medical view of limb pains in children, however authoritative, does not end such discussions. As I write this paper, a newsletter from a local child health centre reports a chiropractor saying that colic in infants was due to injury in the back during delivery. It is hard to refute assertions like this, or astrology, or that hypoglycaemia is a common condition.


In recent months an Australian company launched a back-pack for children, with aggressive advertising. This warned of the danger to children of carrying heavy bags of books to school, weighing an average of 5 kilograms. It quoted a study in which 40 per cent of children were found to have some abnormality of their posture. There was no logical or scientific basis for converting this association of two observations into a causal relationship. It could have been argued that the only worthwhile exercise these children got was carrying a heavy bag for some distance twice a day, in between bouts of creative television viewing.


Hunter Fry is a surgeon in Melbourne with unorthodox views on "overuse injury" in musicians, including young students. His views on re-design of musical instruments, such as a rest to relieve the load on a clarientist's left thumb, are appealing innovations (Fry, 1986). However his treatment of "radical rest" is regarded by most others as wrong, and not supported by independent follow-up, a vital element in medical controversy. The same advice given to school-children with pains in computing classes would devastate their studies. Currently there is concern at the increase in the drop- out rate of students at the University of Melbourne's Faculty of Music in the last three years. While this may be due to increased pressure or poorer selection or teaching, it coincides with publicity about overuse injury in musicians.

An equal concern in the musical controversy is that some performers developing pains and strain have faulty technique, usually too much tension, like the handwriting problems described below. With too much emphasis on other factors, the need to correct faulty technique is being missed. Yet it is already well known from the work of outstanding teachers like Gyorgy Sandor ("On Piano Playing"), and Szende (1971).

Psychological and Somatic Factors

Whatever the controversy about hysterical epidemics in adults, the condition does occur in children. When I was a casualty officer at the Royal Portsmouth Hospital in 1962, 15 girls were brought by ambulance from a crowded pop concert at the Town Hall one evening. All had hyper-ventilation from the excitement and the hot crowded environment. They had typical symptoms of tingling, weaknesses, and faintness. All resolved completely in a couple of hours, hough some needed a calming injection. iuch phenomena are well recognised.

These psychological causes should not obscure the role of other specific problems which can be identified in both adults and children. Because there are measures available to correct them, they.are worth attention by teachers. Like a business journalist who declares ownership of shares being promoted in an article, I have to declare a strong and unorthodox belief in poor handwriting technique as a cause of forearm strain in some office-workers.


Since ball-point pens were introduced in the late 1940's, writers have had to press harder on the paper to write legibly. With most pens, especially cheaper ones, it is necessary to exceed a force of 40 grams weight where previously it took less than one gram to write with a steel nib or fountain pen. Indeed, as increasing force was used, nib pens would start to scratch the paper and bend or break the points, so that teaching of gentleness in hand-writing was built into the tool and the activity. -

Greater forces are needed with ball-point pens that are faulty, or with shiny paper, or multiple carbon copies. Writing with great force when angry also became possible, so that someone who is mentally tense can express physical tension much more readily. Such static loads on muscle (uninterrupted contraction, interfering with circulation of blood in muscles) are carried over to typing on electronic keyboards, where there is much less general body movement than in using an old-fashioned manual typewriter.

Young children, at the age when they are developing their finer motor skills, spend some hours each week colouring in large areas with pencils and crayons. These take the same inordinate amount of force to use. The lack of a relation between effort and result in electronic devices impedes the formation of consistent natural patterns of skilled movement.

Sustained muscle tension leads to ache, and pain, which normally recover with rest, but recurs with more activity. Sometimes the temporary pain becomes locked into memory, and the result is persisting pain. Either effect would explain writers's cramp, about which much has been written since its description by Ramazzini in 1713.

Motor skills in childhood may develop poorly for other reasons, such as less time spent in activities like ball-games. These normally help develop physical coordination and relaxed style for success and satisfaction. In the present context, habits of applying excessive force become ingrained, and their effects can be summarised:

1. "Co-contraction", when agonist and antagonist muscles contract together to give the same final output at the expense of measurably greater muscle activity, which is not productive but leads to fatigue.
2. Tense activity of muscles which are not required for hand-writing, in the forehead, neck, shoulders, and upper arm.
3. Excessive force in gripping the pen, or tools and controls used in other work.
4. Excessive force in carrying out the task - pressing too hard with the pen, or onto a keyboard.

Some of this is obvious to the naked eye - blanching finger-tips, or extremes of finger-joint position, or the bulging of contracted muscles compared with their relaxed state, or movements with quicker stop and start compared with the more slowly accelerating and braking pendular oscillation of relaxed and skilled movements. Sometimes tension is not so visible to the naked eye, and can only be detected by palpation by a physiotherapist or other expert in physical movement.

Much of this was known to the 1911 Report of the Departmental Committee on Telegraphists' Cramp in Great Britain, of which there is a copy in the Sydney Public Library. This contrasted "a free, loose, flowing, easy, and natural style" with "one that is cramped, rigid and unnatural and likely to prove irksome and tiring to the operator" (Patkin, 1984).

A useful tool for demonstrating excess muscle tension is electromyography (EMG). This reads and displays the electrical signals from limb muscles in the same way that an electrocardiograph (ECG) shows the activity of the heart. Portable EMG monitors costing about $1000 are now coming into wide use for re-training adults with some problems. They are taking the mystique out of tension, demonstrating when it is an objective phenomenon, and helping to cure it.

Details of hand-grip

There are many examples of handgrips for writing in books of penmanship from the sixteenth century onwards. All of them show a curved index finger, and gently bent thumb (Fig. 1a).

Today, the common writing grip is one with the thumb pressing so forcibly onto the index fingertip that the end joint is bent backwards 30 degrees or more (Fig. 16). This joint position can not be achieved by contraction of the muscles acting on this joint. It takes a push of 40 grams or more. It leads to significant co-contraction.

The amount of force exerted by many writers is far more than needed even for ballpoint pens of good quality. The simple way of demonstrating this is by having them write on some paper resting on a folded handkerchief or cloth. It is easy to see and feel the indentation of the paper when it is turned over. This same demonstration is also a useful way of correcting this one fault of technique. Other faults, such as cocontraction, need their own special method of correction.

These observations can be correlated with measurements. by having the subject write on a platform on a push-pull gauge. placed next to a table. My "best" patient wrote with a force of 600 grams weight, filling in invoices 2 hours a day and using stale carbon paper. She had always written forcefully. Her true tenosynovitis was cured without surgery, in five days, by changing to a fountain pen.

****** set of diagrams

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Quality of Pens

The quality of pens in general use today varies widely. Some of them write easily, and others require considerable force.

A simple method of measuring this force is to load them with weights to determine the threshold ranges at which writing just starts, becomes more legible, and then becomes reliable. The handiest weights are coins, which can be fixed onto the side of the pen in opposing pairs by adhesive tape (Fig. 2). A 20-cent piece has a mass of 11.714 grams, and pens themselves can be weighed on a diabetic or postage scale. The pen is then supported in a short cylinder of writing paper, and guided across the paper. And when your research is finished, you can use the 20 cent pieces again.


Similar principles to those of handwriting apply here. It is surprising that more research has not been directed to hand- posture in typewriting. Commercial teachers of typing, and their textbooks, have only a few brief dogmatic statements to make about the matter.

When muscle activity in the forearm is measured with an EMG, it is quite clear that the best typing technique is with the wrists straight or slightly bent, and the fingers not too curled (Fig. 3a). Typing with the wrists cocked up (Fig. 3b) gives much stronger EMG signals from just below the outside of the elbow, from the very muscle that becomes sore in muscles with "myalgia". Some typists hit the keys very hard. The best cure for this not obvious yet. One may be to have typists learn to type as softly as possible and still just have the letters start to appear on the screen, and then learn to apply slightly more force.

Some keyboards may have particularly stiff keys. The ideal stiffness is in the range between 50 and 80 grams weight. As with the method for testing pens for their ease of writing, it is easy to tape 20-cent pieces onto an old ballpoint pen or a pencil, six of them for a gono-go gauge of about 70 grams (Fig. 4). The gauge is lowered onto each key in turn by a long tail of adhesive tape, and it is easy to see if the key is actuated or not. It may be necessary to tilt the front of the keyboard up a little if the end of the pen slips off the key.

Key stiffness is not the only aspect of key quality - there are others, which are listed in standard books on the ergonomics of video display terminals. Bad key design is unlikely to be any physical problem for the help of children for the hours they are likely to be using them at school.


Much has been made of how to sit correctly when typing. The most popular advice is for typists to sit upright, with the main joints at ninety degrees (Fig. 5a). This "Teutonic Tsquare" is prescribed at the workplace by a wide range of advisers, many with no training or skills in the area. However it is by no means the only opinion.

A semi-kneeling position (Fig. 5b) has been advocated for seated work, based on studies of school-children (Mandal, 1981). Often they sit on the front edge of their seat, so maintain the normal curve of their lumbar spine when they sit, instead of flattening it. These ideas are incorporated in a heavily advertised chair for office work, which some erognomists call the "Swedish joke". It does not suit many office workers.

James Coe, until recently the director of an advisory service at the Royal Melbourne Institute of Technology, takes an opposite view (Coe, 1979). He advises office workers to sit on a low chair (Fig. 5c), another idea rejected by most ergonomists.





A third view is given by Grandjear. (1984), Director of the Swiss Institute for Industrial Hygiene and Work Physiology. He advocates a more laidback seated posture with the arms straighter than the conventional advice (Fig. 5d).




The implication for seating in schools is that the jury is still not decided. All that one can say confidently is that hunched up and constrained postures adopted as a matter of habit are not advisable, qnd that a large number of experts are ready to give confident advice. Where furniture is the wrong size or shape for a child, it should be modified, but it is hard to say that money for this is more important than for other purposes in schools.

Neck problems

These are controversial, and have not been adequately recognised. They would not affect children at school, but bad habits there could lead to symptoms in workers in their early twenties. Some cases of occupational pain are due to hunching the neck forward at work, due to habit or to too short a focal distance of reading glasses, set for 30cm. instead of the 50cm. or more between the eyes and a computer screen.
This is a difficult matter to investigate in traditional medical ways. Unorthodox therapists - chiropractors, osteopaths, followers of the Alexander technique, and many others - have a large following in the general community because of the apparent success of methods whose scientific basis is argued. However there is now stronger evidence that nerves can be pressed on by structures in the neck through a hunched posture, and that this can be remedied quite simply by attention to neck posture, exercises, and a low pillow at night.

Unfortunately those interested in this aspect of occupational pain have been dogmatic in their own way, and brushed aside other factors in the problem. Like every other view-point on this matter, it is likely to be five per cent correct.

Some implications

The implications of the handwriting factors mentioned above are wide.

If handwriting factors described above turn out to be important, there will have to be some drastic changes to the way that it is taught, and re-taught, throughout school. Standards for pens will also need to be developed and applied. Some research will need to be carried out on the varieties of hand posture and how these relate to symptoms several years later.

Other and more difficult questions will be raised. Do video display terminals emit dangerous radiation? Are children at greater risk of leukaemia if they sit close to a television monitor for several hours a day? The battle lines are drawn up between those who say "not proven dangerous" and others who say "not proven safe". Most people with a normal amount of indifference, or trust, will not be concerned, but an effective minority may establish that in these issues the truth is on the side of caution.

There are more important issues in the health of students than those of occupational strain from keyboards at school. If anyone is at risk of postural problems it should be the obsessive hacker working through the night at home. Other issues, such as teenage smoking, alcoholism, soft drugs, unplanned pregnancy have a wider significance. However if information technology is to be an effective agent in the adult world, it will have to be nurtured through school without the encumbrance of Are-Ess-Eye.


Coe, J. B. (1979). Ergonomics and Visual Display Units: Work Station Design, Ergonomics and Visual Display Units. Proceedings of a Conference, Erognomics Society of Australia and New Zealand.
Fry, H. J. H. (1986). Overuse syndrome of the upper limb in musicians. Med. J. Aust. 144, 182-185.
Grandjean, E. (1984). Postural Problems at Office Machine Work Stations. In E. Grandjean (Ed.), Ergonomics and Health in Modern Offices. Proceedings of the International Conference held at Turin. Taylor and Francis.
Grandjean, E., Hunting, W., & Nishiyama K. (1984). Preferred VDT workstation settings, body posture and physical impairments. Applied Ergonomics 15 (2), 99-104.
Hunter, Donald (1984). Diseases of Occupations. London.
Huxley, A. (1952). The Devils of London. London: Chatto and Windus.
Kerckhoff, A. C. & Back, K. W. (1968). The June Bug: A Study of Hysterical Contagion. New York: Appleton- Century-Crofts.
Lofland, J. (1981). Collective Behaviour: The Elementary Forms. In Social Psychology: Social Perspectives. M. Rosenberg & R. H. Turner (Eds.), pp. 411-446. Basic Books.
Mandal, A. C. (1981). The seated man (homo sedens). The seated work position, theory and practice. Applied Ergonomics, 12 (1), 19-26. Patkin, M. "Trying too hard". An aspect of overuse injury. Proceedings 21st annual conference, Ergonomics Society of Australia and New Zealand. (289-3010.
Rao, H. S. R. (1979). Handwriting Ergonomics. Visible Language, 13 (3). 331-339.
Ross, I. K. J. (1985). Trends in repetition strain injury statistics in New South Wales. J. Occ. Health & Safety Aust. N.Z. 1 (2), 96-101.
Szende, O. & Nemessuri M. (1971). The Physiology of Violin Playing. (translated from the Hungarian). London: Collet's.


The problem in adults
A selective    classification of    common occupational    strains
The are-ess-eye label
The problem in children
Other views
Psychological and    somatic factors
Details of hand-grip
Quality of Pens
Neck problems
Some implications

Occupational strains in school- children - do they exist?

Michael Patkin
Australian Educational Computing, May 1987 pp14-21

"If you don't sit up straight, you'll grow up crooked! - or will you?" Are children at risk of RSI? The answer is a qualified, "No," and this misleading three-letter acronym [RSI] will not be used elsewhere in this paper.

Michael Patkin is a general surgeon in South Australia. He has been interested in Ergonomics for 20 years, analysing skilled hand-grips in surgery and preparing design standards for microsurgical instruments. In 1971 he was awarded a Prince Phillip Industrial Design award. He has lectured abroad extensively and written widely. At present he is particularly involved with software ergonomics. Currently he is president of the Ergonomics Society of Australia and New Zealand, and has been named as lecturer of the year by the Australian Computer Society. In 1985 - he took three months away from his surgical practice to present seminars on "Managing to Avoid RSh: throughout Australia, and is frequently asked to act as an adviser in this area.