SAILORS got scurvy. There was housemaid's knee and hatters going mad with mercury poisoning. Then miners with black lung wheezing their last. Up sooty lums, the dread of an agonising death from cancer of the testes belonged to sweeps. Then came asbestosis and radiation sickness. Every age of work has brought its own peculiar diseases. The end of the manufacturing age was not the end of the story. The legacy of the nuclear industry may be handed down the generations.

Occupational sickness now may be less visible, but to its sufferers it is no less real. This week a former supermarket worker, Mima Rae, launched a civil action for #100,000 against Tesco. She claims her chronic back pain was caused by her work at the chain's checkout in Falkirk. If she were to win, it could result in similar claims from others who believe their back problems are occupational.

Last month, five former Midland Bank workers were awarded more than #50,000 in compensation after winning another test case. They suffered considerable pain in their arms, necks, and shoulders when their work rate was increased. The judge at the City of London Court ruled the bank was in breach of its duty of care to its workers. The women were unlikely to work in similar jobs again. The judgment was seen as a breakthrough for sufferers from repetitive strain injury (RSI), one of the new occupational hazards of the electronic age.

Until recently, RSI was often dismissed as a ''virtual'' affliction, a neurotic rather than a physical response. A spate of recent judgments means the sceptics must think again.

A secretary suffering from RSI who was forced to give up her job after nine years was awarded #5000 by an industrial tribunal in Edinburgh two months ago. Vanessa Matthews developed symptoms of carpal tunnel syndrome in both wrists as well as tennis elbow. She had a voice operated computer installed at the Melrose office to let her continue working. But hostility from management forced her out. The tribunal said it was clear her RSI had been caused by her work.

Extensive new research into the causes of RSI was published in February after a two-year study at University College, London, for the medical charity Action Research.

It found RSI to be a chronic pain condition which may be linked to intensive hand use on computer keyboards or typing. The study provided invaluable ammunition against a 1993 High Court ruling in England by Judge John Prosser who described sufferers as ''eggshell'' personalities and said the condition was all in the mind.

But the research physiotherapist and neurophysiologist who studied RSI patients found that in existing sufferers nerve damage was more obvious after keyboard use. Office workers showed a reduction in vibration sense in the area of the hand supplied by the median nerve, a major nerve to the hand.

The evidence proved that the pain was real, the product of intensive keyboard use. As reported in The Herald earlier this week, a two-year study in Lothian showed that job-related illness accounts for one out of every four trips to family doctors. The pilot project by Lothian Occupational Health Project identified stress, heavy lifting, and hazardous environments as serious risks. Similarly, a survey of working conditions across Europe published late last year by a Dublin-based foundation reported that stress, musculo-skeletal disorders, pollution, and noise were among the rising occupational hazards in the EU.

An employer's duty to take reasonable care and reasonable steps to ensure the safety of employees is covered in Section 2 of the Health and Safety at Work Act 1974 which sets out a duty to provide and maintain systems of work and working environments which are safe and free from health risks as far as reasonably practicable. The Act can be interpreted to cover a risk of mental as well as physical injury. This, along with a small number of recent court judgments, may be why more companies are taking seriously the negative effects of stress. Or at least their insurers are.

In February of this year the Glasgow solicitors Harper Macleod held the latest in its quarterly conferences on employment law for personnel managers. The subject was managing stress levels in the workplace, and it attracted nearly double the usual numbers attending.

The classic case of damages for stress was that of a social services manager in England who was awarded #144,000 by a court. The man worked for a social services department which was heavily overworked. Fellow managers had similar workloads but the man involved had been off work for seven months after a nervous breakdown. His doctor found that the only stressor in his life was his job. The man was unable to work again. The Management of Health and Safety at Work Regulations, introduced in 1992, means that employers are required to carry out risk assessment.

At some time or other, most keyboard users experience stiff necks, sore backs, or cramped hands from excessive use. But computer use is not the only source of consistent symptoms that can lead to RSI.

Dressmakers, butchers, carpenters, and musicians, too, can face these types of injuries. However, international studies have shown that the incident of computer-related RSI has increased most rapidly among business users as more and more companies go on-line.

The emergence of the World Wide Web, e-mail, and a trend toward individuals managing their own correspondence and generating their own reports have spread the risk of RSI to all office computer users.

Work can be a huge pain in the neck too for those whose job involves spending the day on the telephone. The advent of telemarketing has brought its own occupational problems. Cradling the phone between the head and shoulder can produce neck pain and lead to cervical spondylosis, which is described by doctors as wear and tear in the vertebrae or bones in the neck.

Prolonged shortening of the small neck muscles, while sitting motionless on the phone, can crush nerves and blood vessels which travel from the neck to the arm and hand causing pain and dysfunction.

Improving office ergonomics, supplying decent desks and proper chairs, and insisting on half-hourly breaks can help avoid long-term damage.

Other studies have shown that heavy overwork is not only detrimental to health but bad for business. We are working more and more, it seems, to less and less effect. For stressed, worried, and tired workers are less efficient and more often off sick.