Repetitive Strain - Is It Real?

First published in The Lawyers Weekly January 19, 2001,  Vol. 20, No. 34

It is an intriguing idea. If cumulative minor injury causes the knee joints or the intervertebral discs eventually to deteriorate, perhaps typing at a keyboard will ultimately result in worn-out ligaments and tendons.

Unlike soccer injuries, however, no-one is suggesting that an individual key-stroke is traumatic, but perhaps a hundred thousand or a million repeated finger movements finally take their toll on the body.

Of course, under other circumstances, repetitive movements are undertaken for hours each day for the purpose of strengthening or perfecting. The activity is then known as "exercise" or "practice."

Nineteenth century composer and schizophrenic Robert Schumann tore the ligaments and tendons by attaching weights to his pianistic fingers for the purpose of increasing muscular strength. Under more normal circumstances, professional musicians practise, and the creators of computer software keyboard, for many hours every day for years.

The Occupational Safety and Health Administration (OSHA) defines Work-Related MusculoSkeletal Disorders (WRMSDs) as "injury or illness of the muscles, tendons, ligaments, peripheral nerves, joints, cartilage [including intervertebral discs], bones, and/or supporting blood vessels in either the upper or lower extremities, or back, which are associated with musculoskeletal disorder work-place risk factors and which are not the result of acute or instantaneous events (e.g., slips or falls)."

Despite the major impact of WRMSDs on national economies, there is virtually no quality empirical research on Causation. The very phrase, "musculoskeletal disorder work-place risk factors" begs the question by implying incorrectly that such factors have been identified independently. No research has shown the presence or absence of a given ergonomic factor significantly increases or decreases the probability that symptoms will develop.

In those suffering from the symptoms, there is no demonstrable relationship between severity of complaint or disability and degree of the supposed ergonomic stress.

There is no convincing evidence for a causal relationship between work activities and these disorders. Almost all studies purporting to show a causal relationship involve self-reported symptoms or self-reported ergonomic hazard exposure or both.

Hitherto no conclusive study causally links objectively-confirmed diagnoses to objectively-measured ergonomic hazard exposure. Such high quality Evidence Based Medicine investigations as exist have found that most studies of occupational Causation of upper limb conditions lack validity. The more specific and objective the diagnosis, the less evidence is there for a causal relationship with work activities.

By the early 1990s, Repetitive Strain Injury and Cumulative Trauma Disorders accounted for a fifth of all US workers’ compensation costs and for 60% of all new cases of occupational illness in the US. The average claim cost 50% more than the average acute traumatic injury.

Billions of dollars, then, are being paid annually in compensation for conditions that lack an empirical scientific basis.

The American Society for Surgery of the Hand (ASSH) has been vocal in warning about the economic and health consequences of official and clinical endorsement of such unsubstantiated concepts. Similarly, a panel of upper limb surgeons in a report commissioned by the Industrial Injuries Advisory Council from the British Orthopaedic Association "failed to come up with sound objective evidence for occupationally related repetitive strain injury."

An epidemic of Repetitive Strain Injury claims in Australia peaked in the mid-1980s. Whole government offices were shut down - though offices of private industry in the same buildings were not affected by the epidemic. Workers compensation premiums approached 50% of payroll in some industries, and a billion dollar Workcare debt materially contributed to the bankruptcy of the government of Victoria. Eventually, on the basis of stricter criteria for "diagnosis" and some influence of scientific rigour, more claims were denied, particularly in the higher courts. The hemorrhage of the country’s resources was staunched - temporarily.

How should claimant and defence counsel deal with this common problem, given the continuing controversy in the medical community? At least part of the dispute may arise in "humpty dumpty" semantics, "when a word is used, it means what I want it to mean."

Physicians should be held accountable for their diagnoses. The era of authoritarian "black box" diagnosis is past history, and clinicians can and should be required to dissect the essential and confirmatory components that cause them to make one diagnosis rather than another.

By way of example, diagnosis of Carpal Tunnel Syndrome in the medicolegal setting has been found to be incorrect more often than correct, because insufficiently rigorous criteria are applied. The National Institute for Occupational Safety and Health (NIOSH) does not require nerve conduction testing for diagnosis of Work-Related Carpal Tunnel Syndrome, even though this requirement is accepted by most physicians. As a result, half of the patients fulfilling the NIOSH criteria have no abnormality of the median nerve, and a quarter of those not fulfilling the criteria do have a delay in median nerve conduction, the gold standard for diagnosis.

Investigators asked the question, "What do doctors mean by tenosynovitis and repetitive strain injury?" Twenty-one of 24 orthopedic surgeons specifically excluded tenosynovitis from Repetitive Strain Injury by definition, whereas the majority of non-orthopedic medical practitioners included the condition.

If occupational causation of RSI cannot be medically-validated, can the claimant lawyer nevertheless depend on evidence-based medical opinion to assist an insured sickness disability claim? The clinical process is no different than that of assessing legal disability (medical impairment) in any medical condition that has little or no observable or measurable abnormality. Even though the pathological mechanism may not be explained, symptoms that interfere with normal functioning and are not fabricated are compensable, unless contractually excluded.

So-called "Repetitive Strain" results in disability even though there is no sound evidence that it is occupationally Caused.

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