A study comparing office workers with patients suffering from RSI found measurable differences in their response to vibration which worsened among the patients after five minutes of typing. The findings, the first to demonstrate that RSI is a medical condition with a physiological basis, could lead to the development of a test for the condition.
Scepticism about the true basis of RSI, which affects thousands of employees and has left many unable to work, has made it difficult for sufferers to gain support or win compensation. Although the condition is associated with long hours spent working at computer keyboards, it affects a range of industrial workers who perform repetitive movements, from chicken pluckers to toilet-roll manufacturers.
The research, conducted at University College, London, and published in the International Archives of Occupational and Environmental Health, used "vibrometer" tests on keyboard and non-keyboard users and found that RSI sufferers had reduced vibration sensitivity in the area of the hand supplied by the median and ulnar nerves. They felt normal pressure in this area as pain, indicating nerve damage. The study, funded by the medical charity Action Research, was conducted on 29 office workers, 17 patients with RSI and 27 controls who did not use computer keyboards regularly.
The Trades Union Congress, which claims that 100,000 keyboard workers and a similar number in other jobs suffer RSI, said the finding would help the worst affected win compensation. John Monks, TUC general secretary, said: "Tens of thousands of sufferers can take some comfort today from this evidence proving their pain is real - the product of intensive computer use. The dangers of computer over-use should now be clear to employers and their insurers and they must take urgent steps to ensure that the work they are giving their staff is safe."
The finance union BIFU, which is awaiting the outcome of five test cases involving Midland Bank employees who worked on in-putting cheque and other information to computers to strict time limits, called for RSI to be a recognised industrial injury which would allow sufferers to qualify automatically for industrial injury disablement benefit.
Tom Jones, a personal injury lawyer with the London law firm, Thompsons, which handles several hundred RSI claims a year, said compensation was easier to win in cases of "pathological" RSI where there were clear physical symptoms - "lumps and bumps". "Diffuse" RSI, where there were no physical signs, was much harder to prove.
"This study suggests it is possible to prove injury in diffuse RSI. It is the first step on the ladder to giving some credence to those people who claim their injuries are caused by their work."