New study finds link between RSI and a loss of performance from sensory nerves in the arm

HSE Press Release E119:02 - 16 July 2002

Research commissioned by the Health and Safety Executive (HSE) has found a link between RSI and abnormalities in the way sensory nerves work in the arm.

Scientists examined the hands of 45 RSI patients and 40 office workers whose results were compared with those from a control population of 44 people. The researchers studied three indicators of the way nerves function: the ability to detect a vibration stimulus at the finger tips, the ability of the skin to respond to small injuries and the reduction in blood flow to the skin following exposure to cold temperatures.

The research found that vibration perception thresholds were up by 45 per cent in RSI patients and by 21 per cent for office workers - which showed these groups were less sensitive to vibration. Also the flare response after small injuries, showed comparable reductions in area; 33 per cent for patients, 30 per cent in office workers; and intensity; 43 per cent for patients and 41 per cent for office workers. In the third test the constriction of blood vessels was reduced by 20 per cent in patients compared with the controls.

A separate part of the study used imaging techniques to look at changes in the way the median nerve moves inside the carpal tunnel - where the nerve passes between the bones of the wrist - when the wrist is bent. Two imaging techniques, magnetic resonance and ultrasound scanning, were tried and their results found to be in agreement. When ultrasound imaging was used to study movement of the median nerve at the wrist when it is flexed and extended, four out of 10 office workers showed only small or reversed nerve movement, a pattern seen more often in patients. These latter results are not conclusive.

Ron McCaig, of HSE, said:

"This research found that there is evidence of a modest loss in peripheral nerve function in RSI patients and that office workers who do a lot of keyboard work demonstrate similar but not as marked effects. These findings confirm the results of previous more limited studies and will be used to develop Health and Safety Commission's priority programme which aims to reduce work-related musculoskeletal disorders."

Notes to editors

1. This project was part of HSE's ongoing programme of biomedical research. The HSC's musculoskeletal disorders Priority Programme aims to reduce the incidence of work-related illness involving musculoskeletal disorders by 20 per cent, and reduce the number of working days lost due to these disorders by 30 per cent over the next eight years. HSE aims to achieve the targets in the programme by communicating effectively with all stakeholders (such as employers, employees, and health professionals) to encourage ownership of the plan and its outputs, keeping them informed, and giving them opportunities to contribute, revising the strategy as necessary.

2. Work making significant use of display screen equipment is subject to the Health and Safety (Display Screen Equipment) Regulations 1992. The Regulations give employers duties to assess and reduce risks, ensure workstations meet minimum requirements, plan work so there are breaks or changes of activity, provide eye tests on request, and give information and training to users. Complying with the Regulations will help to prevent musculoskeletal disorders such as RSI. HSE has published guidance on the Regulations, including a free booklet "Working with VDUs" available on the HSE website.

3. The research was jointly funded by HSE and the British Occupational Hygiene Research Foundation (BOHRF) and undertaken by University College London. Full details of the findings can be found in HSE's contract research report 417/2002 entitled Sensory and autonomic function and ultrasound nerve imaging in RSI patients and keyboard workers.

Sensory and autonomic function and ultrasound nerve imaging in RSI patients and keyboard workers is available on the HSE website at www.hse.gov.uk/research/noframes/crr/index.htm

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