MOST people who use computer keyboards regularly will develop nerve damage in
their arms, a new study suggests.
鈥淭his is a startling finding,鈥� says Bruce Lynn, the neurophysiologist at
University College London who led the research. 鈥淲e may be seriously
underestimating the number of people who are at risk from upper limb disorders.鈥�
He says the study provides the best evidence yet that repetitive strain injury
(RSI) is a real physical illness.
To investigate RSI, Lynn and his colleague Jane Greening studied three groups
of people: patients being treated for the condition; a group of office workers
who regularly used keyboards; and a control group who did not.
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With each group, they applied vibrations to different parts of the hands to
test the sensitivity of the three main nerves running up the arm: the radial,
the ulnar and the median. This technique has been important in studying more
established forms of nerve damage.
The 17 people being treated for RSI were less sensitive to low-amplitude
vibration than the 27 in the control group. This reduction in sensitivity was
most marked in the median nerve. The RSI group also felt pain when their arms
were subjected to high-amplitude vibration.
Only three of the 29 keyboard-using office workers were complaining of RSI
symptoms at the time of the test. Yet 60 per cent showed a similarly large
reduction in their median nerves鈥� sensitivity to vibration. 鈥淭his may indicate
the first signs of RSI,鈥� says Lynn. He argues that the discovery could lead to
tests that would give an early warning to people at risk of developing
upper-limb disorders.
Lynn says his results, which appear this week in the International
Archives of Occupational and Environmental Health (vol 71, p 29), fit the
theory that RSI relates to damage of the median nerve. 鈥淵ou would assume from
this that nerve fibres have been damaged or have died,鈥� he says.
The study should strengthen the case of RSI sufferers struggling to convince
employers and the courts that their condition is work-related. 鈥淭his proves what
we鈥檝e been saying,鈥� says Tim Gopsill, health and safety spokesman for Britain鈥檚
National Union of Journalists. 鈥淩SI is a real condition that causes serious
辫补颈苍.鈥�
However, a spokeswoman for Britain鈥檚 Health and Safety Executive (HSE) argues
that a precise definition for RSI remains elusive: 鈥淩SI is not a formal medical
condition, but we accept that working on a keyboard can affect people鈥檚
丑别补濒迟丑.鈥�
The HSE has launched two studies in the hope of gauging the number of people
who suffer work-related pains in their arms. 鈥淚t鈥檚 not just keyboard workers,鈥�
says the spokeswoman. 鈥淲e鈥檙e looking at everyone from supermarket checkout
people to factory workers.鈥�
