Repetitive Strain Injury (RSI) is a physical condition and could be diagnosed by a simple test, scientists have said.

A research team at University College, London, tested the movement of a nerve in the wrist in people who complained of suffering from a non-specific pain in their forearm, thought to be RSI.

RSI is a highly controversial condition that affects people who repeatedly carry out the same task, and thus use the same muscles and tendons again and again.

For instance, people who use a keyboard in their work such as secretaries, typists and journalists are thought to be particularly at risk.

Although some people complain of constant pain and have been unable to continue to work, some experts believe that RSI is a psychological condition with no physical cause.

Symptoms include:

• Tingling or burning sensations in the hands, wrists or arms
• Persistently stiff or tense shoulders or back
• Unusual but persistent tiredness, discomfort, or inability to concentrate.

The researchers used both a hi-tech magnetic resonance scanning technique and a clinical test commonly used by physiotherapists.

Both tests provided physical evidence that patients with RSI had reduced movement of the median nerve when they flexed and extended their wrists.

Trapped nerves

Typing has been linked to RSI

This suggests that the pain experienced by RSI sufferers may result from the nerve being trapped or compressed by tendons in the wrist, which are known to swell up if over-used.

The researchers say that the nerve test could be a cheap way to diagnose the condition.

Physiotherapist Claire Sullivan said that the study at last proved that RSI was a genuine physical condition, and dismissed those who cast doubt on its existence on the grounds that it was a phenonmenon of the last decade.

She said: "There have been reported cases of RSI for two or three hundred years. It is only recently that it has come to the forefront of people's minds."

The Chartered Society of Physiotherapy called for RSI to be recognised as an industrial injury to ensure that sufferers have access to specialist treatment.

CSP chief executive Phil Gray said: "The weight of scientific evidence that diffuse RSI has a physical cause is such that it can no longer be dismissed by sceptics as a figment of the sufferers' imagination.

"RSI must now be recognised as an industrial injury. With this official status, employers will be compelled to protect their staff.

"This means regular risk assessments, guaranteed, regular breaks from repetitive tasks, training on how to avoid injury and jobs designed around staff and not the other way round."