Musculoskeletal disorders, and particularly those affecting the upper limbs, are the most common occupational illness in the UK, but there is much that can be done to prevent, or alleviate them if their causes and symptoms are understood, says Dr Chris Ide.
Work-related upper limb disorders (WRULDs) comprise a wide spectrum of diseases, whose range extends from the neck to the tips of the fingers. The names of these conditions — deriving from the part of the body affected and the victim’s occupation — include the likes of Fishwife’s Finger, Upholsterer’s Hand,
Gamekeeper’s or Sausage-maker’s Thumb, Cotton-twister’s or Pizza-cutter’s Wrist, and Tennis or Golfer’s Elbow — not to mention Hop-picker’s Gout and Slaughterer’s Shoulder (OK, I made that last one up!)
In the UK, estimates of the number of cases of WRULDs vary widely. Officially compiled statistics show that in 2006/07, 435 cases of carpal tunnel syndrome and 145 of tenosynovitis were compensated through the Prescribed Diseases scheme.1 However, these figures are likely to understate the scope of the problem, since the criteria applied are very stringent. At the other end of the scale, according to the Labour Force Survey, 1.44 million workers believe they have a musculoskeletal disorder that has been caused, or made worse, by work, with about one third of those relating to the upper limbs.2 The extent may be over-estimated, since the diagnoses are self-reported, and the attribution of the disorder to work activity may be wrong.
On the other hand, we have little way of knowing how many people have a health problem caused by work, but are unaware of the connection. A third scheme, run by the University of Manchester, collects reports from occupational physicians and consultant rheumatologists, and suggests that about 23,800 cases occurred over the four years up to and including 2006, with upper-limb disorders accounting for more than 60 per cent.3
While the quality of diagnosis is good, there are other problems with under-reporting, since only a small minority of employees work for organisations that have any form of occupational-health provision whatsoever, and about 90 per cent of all episodes of health problems are dealt with entirely within general practice.
Almost 20 years ago, a group of GPs who had occupational medicine qualifications and worked part time for the Employment Medical Advisory Service surveyed their work over the course of a year. They found that between 5 and 7.5 per cent of all first attendances for new health problems of their patients aged 16 — 65 were caused, or worsened, by work. Musculoskeletal problems occurred most often. (Unfortunately, this study was not published.)
To fill this gap, another reporting scheme, also organised by Manchester, has started to accumulate data submitted by general practitioners with an interest in occupational health. Early reports suggest that musculoskeletal problems in general occur frequently, and are responsible for more than 50 per cent of all work-related ill health seen in general practice, particularly in the retail, agricultural, food manufacturing, land transport and construction sectors.4
But WRULDs are also prevalent among office-based workers. Bernardino Rammazini, in his book De Morbis Artificum Diatriba, published in 1713, described Clerk’s Palsy thus: “Incessant driving of the pen over paper causes intense fatigue of the hand and whole arm…failure of power in the right hand.” Charles Thackrah, author of The effects of the arts, trades and professions on health and longevity noted of accountants, book-keepers and clerks that “their muscles are distressed by the maintenance of one posture”.
Readers may well remember the blizzard of repetitive strain injuries (RSI) that afflicted workers in Australia 25 years ago, but then rapidly fizzled out after a few years. Operators of word-processing equipment featured prominently in this “outbreak”, which, by 1989, had cost in the region of £220m. The Australian epidemic eventually expired (or returned to normal background levels) for a variety of reasons: successful defence against some of the more outrageous claims, a change in the way in which diseases were classified, and because some researchers started to look beyond the medico-legal hullabaloo to investigate and attempt to remedy some of the underlying problems.
These included issues of job security, which arose because of the rapid introduction of new technology, job dissatisfaction, political activism, and workplace relationships between employees. This partly explained why, in an office in Sydney, 25 per cent of a group of workers claimed to have developed symptoms, compared with just 4 per cent of employees doing the same job with identical equipment in Melbourne. For the first time, the importance of workstation and workplace design came to be appreciated.5, 6
Conditions of service
The predominant symptoms of WRULDs encountered in today’s workplace are pain, parasthesiae (pins and needles), stiffness, and weakness. While a number of disorders present with clearly defined symptoms, and have an established pathological/ anatomical basis with reproducible results for various physiological tests, in the case of many others the symptoms and signs are often more vague — these were the so-called repetitive/repetition strain injuries (RSI). These conditions include:
Carpal Tunnel Syndrome (CTS)
This disorder affects between 3 and 5 per cent of Americans, women about three times as frequently as men, and is caused by the median nerve becoming compressed as it passes through the carpal tunnel in the wrist. The principal symptom is pain, which affects the thumb, first two fingers, and lateral aspect of the ring finger (with the palm uppermost). It is worst at night, often rousing the sufferer from sleep. A flicking motion of the affected hand will eventually cause the pain to subside but, if symptoms persist, weakness develops and quite striking wasting of the muscles at the base of the thumb can occur.
The ‘gold standard’ for diagnosis involves studies of nerve conduction. While certain work environments can provoke CTS, there are many non job-related disease triggers that need to be sought and, if present, treated (hence the importance of having medical advice available). In Washington State, workers’ compensation cases were responsible for cumulative wage losses of between $45,000 and $89,000 in the six years post-injury.7
Tenosynovitis (of the wrist)
In this condition, there is inflammation of the tendon sheaths, tunnels through which the tendons that bend and straighten the wrist and fingers pass. This produces pain on resisted movement, and a sensation called crepitus, which feels and sounds like scrunching cornflakes inside their wax packaging. There are two particular sub-types of tenosynovitis — de Quervain’s, which affects the tendons that straighten the thumb, and ‘Trigger finger’ or thumb, which causes symptoms involving the tendons that straighten the digits.
Tennis and Golfer’s Elbow
These two conditions are of uncertain origin, but are associated with tasks involving heavy tools, and forceful or repetitive motion. Tennis elbow is the more common of the two.
Shoulder tendinitis
This painful condition arises from inflammation or degeneration of the tendons that surround the shoulder joint. This damage may be done by an acute injury or, more probably, the imposition of repeated minor strains on tissues damaged by the aging process. Scanning may show evidence of tears and other damage.
Earlier, I wrote that I had made up a diagnosis of Slaughterer’s Shoulder. In fact, while researching medical publications for the purpose of this article, I came across a paper, which described shoulder problems in chicken processors. The workers frequently raise their hands above shoulder height to pinion the birds’ legs to travelling shackles and develop persistent shoulder pains.8
Indefinite articles
This is by no means a complete list of medically recognised upper-limb problems. By a process of exclusion, we are left with a category of miscellaneous disorders in which symptoms of pain and weakness predominate, but the areas affected do not always correspond to the distribution of a particular nerve or muscle group. There are no blood, imaging, or physiological tests which can aid the diagnosis. This is probably the reason why so many different names, such as Repetitive Strain Injury, Cumulative Trauma Disorder, Regional Pain Syndrome and Occupational Overuse Syndrome have been adopted.
Medical, surgical and manipulative treatments, such as physiotherapy, osteopathy and chiropractic, are available for all of these conditions, but success is by no means certain, and may take months, or even years. One of the aims of treatment should be an early return to work, but relapse will almost certainly occur if the job that may well have triggered the condition has not been modified.
If doctors are involved, it is important that they make a meticulous enquiry and examination. This is even more relevant if there is more than one case in the workplace. In these circumstances, the use of diagnostic criteria laid down by Harrington and others can ensure a consistent approach.9
What sometimes makes attribution difficult is the fact that neck and upper-limb symptoms are very common in the general population. For example, Bongers reported that shoulder pain was reported by between 14 and 20 per cent of survey populations at the time of interview, and that up to half these groups had endured shoulder pain at some point in the preceding year.10 Up to 3 per cent of those questioned may be suffering from symptoms compatible with Tennis or Golfer’s elbow.11
Leisure-time interests further complicate the issue. When someone is referred to me for an opinion or advice, I always make a point of enquiring about their hobbies. This enables me to form a more holistic picture of the individual, and allows me to assess the effect that non work-related events may have on the totality of symptoms. When asked, a surprising number will say ‘computing’, and will admit to spending several hours a week at the keyboard, or playing games.
This can give rise to the conditions known as ‘Nintendonitis’ and ‘Wii knee’ (albeit both cases described in children under 16!)12, 13 Some keen fly-fishers will tie their own flies and, occasionally, some sports enthusiasts will admit that their elbow pain may be the product of golf or tennis.
Indeed, this article was prepared on a word processor during my spare time, at a workstation that might not exactly comply with the DSE Regulations! Much of my research is also carried out away from work. Several years ago, I was crunching some numbers for a paper I was writing. The results generated were really exciting, and I worked on and on, ignoring the increasing ache in both forearms, until I was unable to pick up a mug of tea. Fortunately, the symptoms abated quickly and I learned my lesson. My main regret is that I did not submit a paper on the new disease, ‘Researcher’s Wrist’!
This sort of thing becomes much more serious when one considers the way in which the distinction between work and leisure is becoming blurred. The tendency to encourage people to work from home to reduce unproductive time spent commuting, or carbon footprint, means the home becomes a workplace, so employers must ensure that workstations comply with relevant health and safety legislation and best practice.
Fast and furious
So far, the discussion has confined itself to work involving keyboards. While such problems have hogged the limelight, many other jobs can give rise to upper-limb symptoms and disability. Rather than work my way through the jobs listed in the Standard Occupational Classification, I will say that upper-limb problems are much more likely to occur in tasks that require maintenance of static postures, together with rapid, repetitive, forceful movements in which the joints are held in positions near to the extreme of their range of movement. Sample occupations include musicians, bakers, butchers, checkout operators, cleaners, garment-cutters, secretarial workers, process-workers, packers, and telephonists, to name but a few.
The role of the practitioner
Although reaching the specific diagnosis and recommending treatment is a medical task, addressing the working environment to reduce the chances of relapse and — even better — to prevent others developing the same difficulties, or to stop the problem developing in the first place, is the role of the employer, with the help and advice of their health and safety staff.
Health and safety officers (and occupational health staff, for that matter) need to spend time in the workplace seeing what actually goes on, and gaining the confidence of employees and supervisors. It does no harm to consult the HR department, either — what’s staff turnover like/why do people leave us? (Could it be because people are fed up of leaving work with persistently aching limbs at the end of the day?)
Many upper-limb disorders, particularly those affecting the extremities, are made worse by cold. This is possibly because cold reduces the blood flow, lessening the supply of nutrients to, and removal of waste from, the tissues. Vibration may also produce the same effects. Gloves may help with warmth, but they need to be chosen very carefully, since manual dexterity may be impaired, and sensation reduced, resulting in clumsiness and tighter gripping.
With increasing numbers of women now in the workforce, and doing jobs that were previously the preserve of men, it is important to ensure that tools and equipment can be adapted for women’s use. Bear in mind also that muscle power is needed to operate tools, and this obviously differs between men and women. Women generally have smaller hands than men, so being able to comfortably hold and operate handles, etc. makes tool design another issue.
Work activities can be quickly screened using a checklist, such as the Quick Exposure Check.14 It is also important to explore organisational and cultural issues, using the bio-psycho-social approach.15
Conclusion
WRULDs probably emerged alongside civilisation itself, and will likely continue to dog humankind for the foreseeable future. Although not as life-threatening as traditional occupational diseases, such as silicosis and lead poisoning, they may greatly impair the quality of life for some, and divert valuable resources away from more effective or relevant use. By seeking out and getting to grips with these problems, appropriately trained, motivated and resourced health and safety staff can make a significant contribution to the economic and social well-being of the organisations that employ them.
References
1 www.hse.gov.uk/statistics/tables/iidb03.htm
2 Labour Force Survey (2007): Self-reported work-related illness and workplace injuries in 2006/07 — www.hse.gov.uk/statistics/ lfs/lfs0607.pdf
3 McRorie, E (2008): Annual Abstract of Statistics 2008, I Table 9.8 p 137, Office of National Statistics, Palgrave McMillan
4 Thorley K, Hussey L, Agius R (2008): ‘Health, work and the general practitioner’, in Occup Med 2008, 58;4:233-235
5 Huskisson, E C (1992): ‘Repetitive Strain Injury — The Keyboard Disease’, Charterhouse Conference and Communications Ltd, London
6 Ferguson DA (1987). ‘RSI: putting the epidemic to rest’, in Med J Aust 1987; 147:213-214
7 Foley M, Silverstein B, Polissar N (2007): ‘The economic burden of carpal tunnel syndrome: long-term earnings of CTS claimants in Washington State’, in Am J Ind Med 2007;50:155-172
8 Buckle, P (1987): ‘Musculoskeletal disorders of the upper extremities: The use of epidemiological approaches in industrial settings’, in J Hand Surg 1987; 12A:885-889
9 Harrington, JM, Carter, TJ, Birrell, L, Gompertz, D (1998): Surveillance-case definitions for work-related upper-limb disorders’, in Occup Environ Med 1998, 58;4:264-271
10 Bongers, PM (2001): ‘The cost of shoulder pain at work’, in Brit Med J 2001, 322;7278;64-65
11 Ryder SJ, Bird HA (2007): ‘Rheumatological disorders’ in Fitness for work — the medical aspects, Eds Palmer, KT, Cox, RAF, Brown, I; Faculty of Occupational Medicine, Oxford University Press 4th. edn
12 McGregor, DM (2000): ‘Nintendonitis? A case report of repetitive strain injury in a child as a result of playing computer games’, in Scott Med J 2000,45;5:150
13 Robinson, RJ, Baron, DA, Grainger, AJ, Venkatesh, R: ‘Wii knee’, in Emerg Radiol — www.springerlink.com/content/ 66124587g682v28g/ — accessed February 2009
14 David, G, Wood, V, Li, G, Buckle, P (2008): ‘The development of the Quick Exposure Check (QEC) for assessing exposure to risk factors for work-related musculoskeletal disorders’, in Applied Ergonomics 2008,39;1:57-69
15 Burton, AK, Kendall, NAS, Pearce, BG, Birrell, LN, Bainbridge, LC (2009): ‘Management of work-relevant upper-limb disorders; a review’, in Occup Med 2009,59;1:44-52
Chris Ide is an occupational physician and regular contributor to SHP.
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