RSI and the brain

Citation

Rudall, B.H. (1999), "RSI and the brain", Kybernetes, Vol. 28 No. 9. https://doi.org/10.1108/k.1999.06728iaa.001

RSI and the brain

Keywords Automation, Cybernetics, Research, Technological developments

Abstacts Reports and surveys are given of selected current research and development in systems and cybernetics. They include: RSI and the brain, Innovations, Biocybernetics, Mathematics and cybernetics, Molecular devices, Devices controlled by thought, Automation and cybernetics, VDU radiation.

RSI and the brain

New research on RSI

Repetitive strain disorder (RSI) may be a disorder of the brain some researchers believe, rather than one of the hand or wrist. Cyberneticians and systemists are well aware that our present human-machine interface means that computer users have to continually use keyboards and other hand-operated devices. Even the mouse-operated personal computer involves hand usage.

At the University of California, USA, researchers say that patients suffering from RSI need to retrain the way parts of the hand are mapped on to those parts of the brain that control touch and movement. Professor Nancy Byl, a physical therapist at the Californian University, is reported to use blindfolds as a way of forcing patients to make the very precise movements needed to count the dots on a set of dominoes which she uses in this, the latest radical treatment for the RSI condition.

Other exercises include identifying letters or numbers traced on to the patient’s fingers. The aim behind this strategy is that such activity sharpens the sense of touch and will result in retraining the brain to control delicate movements more efficiently.

The researchers have conducted experiments that have, they say, supported this theory. They created RSI in owl monkeys. In order to get a tiny amount of food, the monkeys had to squeeze a pistol grip. This simulated the action of many humans in their daily occupations. After a few months, it is reported, the animals showed signs of pain and stiffness. The experimenters say that the monkey’s hands became clumsy and suffered muscle spasms in the same way that human hands do. It appears that the constant repetition was causing their brains to lose track of which finger was which.

The region of the brain where touch sensations from all over the body are handled has been identified and named as the sensory cortex. In this section we are told that there are different areas which are responsible for the feet, the legs, another for the face and so on. The report on this research says that:

This "map"; is very precise: a touch on different fingers, even of different parts of the finger, fires off different clusters of cells in the sensory cortex. This map is also constantly being redrawn, depending on how much you use a particular area. If you learn Braille, for instance, the number of cells responding to the tips of your fingers increases.

It is considered that normally, this process, as described, would be a helpful one. In the case, however, of the owl monkeys used in these Californian University experiments, and indeed with human keyboard users and typists in general, as well as, for example human pianists, the brain tries to deal with very complex and fast sequences by rewiring the maps. As a result they become much less precise and lead to clumsiness. Ultimately it results in the pain which sufferers know is the main characteristic of RSI.

The report of the experiments with the owl monkeys says that:

When they were tested (the owl monkeys) some of the neurones responded, not just to a touch on a small part of the finger, but to anywhere on the palm of the hand. Something similar seems to happen to humans with a particular sort of RSI known as focal hand dystonia – a condition particularly common among musicians.

Researchers say that brain scans on unaffected people show that the brain cells that respond to a touch of the thumb or the little finger are about 12mm apart. In dystonia patients, we are told, the same neurones fired for both digits.

New treatments for RSI

A report in the UK’s Daily Telegraph (July 1999) by Jerome Burne gives details of some of the new treatments that are being developed as a result of this work. Obviously the research is at an early stage but with current treatments focusing on the hand or wrist and involving immobilising the arm, massage or even surgery, it is to be encouraged. If Dr Byl and her fellow researchers are right these techniques, Burne says, could be missing the point. One small trial is reported which so far is said to be very promising. It involved eight patients, four computer users and four sign-language interpreters, each with severe pain in the wrist and hand. They were treated with sensory retraining and the results monitored. Within an hour, it is reported, several said their pain had eased and, after three months, all had recovered sufficiently to return to work.

As with many such experiments the "placebo effect" has to be considered and the results viewed accordingly. Obviously more work and trials are contemplated and appropriate statistical analysis will become available.

In the UK a “wait and see” approach is being taken and Dr Bruce Lynn of the University College, London is reported as believing that:

This model does look like a good model for dystonia. But I am not sure it is so applicable to the more common forms of RSI which involve less clumsiness but more pain.

We look forward to examining the results of more research and trials. Meanwhile Professor Nancy Byl and her fellow researchers will continue with their experiments and trials using their radical treatment. In the UK Dr Lynn is looking for companies to take part in trials aimed at reducing the incidence of RSI. She can be contacted at the University College, London (UK Telephone: 0171 380 7334).