High quality trials and evidence of effective treatments for repetitive strain injury (RSI) are needed to define this controversial condition which affects millions of patients worldwide. The findings are reported in a Seminar published in this weeks edition of The Lancet.

Professor Maurits van Tulder, EMGO Institute, VU University Medical Centre, Amsterdam, Netherlands and colleagues did extensive research into the prevalence, causes, symptoms, and treatments of RSI using a number of medical databases.

The authors say: "Repetitive strain injury is not one diagnosis, but is an umbrella term for disorders that develop as a result of repetitive movements, awkward postures, sustained force, and other risk factors."

Conventional definitions of RSI include specific disorders such as carpal tunnel syndrome (a twisting of the median nerve at the wrist causing pain in the wrist and hand), tendonitis of the wrist and hand, and various upper limb problems.

RSI arises frequently in adults of working age, with many people reporting strains of the hands, wrists, arms, shoulders or neck. Several countries report RSI incidence of 5-10%, although this could be as high as 40% in specific working populations.

Several hypotheses exist for how RSI occurs, but none have been supported by strong scientific evidence. One theory is that continuous contraction of muscles from long term static load with insufficient breaks could result in reduced local blood circulation and muscle fatigue. Consequently, pain sensors in the muscles could become over-sensitive, leading to a feeling of pain at lower-than-normal thresholds. Another theory is that overuse of tendons by repetitive loading causes RSI.

Diagnosis is often a difficult proposition. The authors say: "No gold standard tests for repetitive strain injury exist. In most cases, diagnosis is made on the basis of history and physical examination, including assessment of range of m
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Contact: Maurits van Tulder
mw.vantulder@vumc.nl
31-204-448-178
Lancet
24-May-2007