Median nerve latencies in poultry processing workers: an approach to resolving the role of industrial "cumulative trauma" in the development of carpal tunnel syndrome.

Much attention has been paid recently to a claimed connection between stressful repetitive motion at the work site and the development of carpal tunnel syndrome. Little of this has made its way into the widely appreciated medical literature. To try to discover a reasonable basis for the presence or absence of such an association we measured median nerve motor and sensory latencies in a random sample of employees in a medium industry of the kind thought to be associated with the emergence of carpal tunnel syndrome. A control group made up of applicants for positions of this sort was used. No association between employment experience and the development of slowing of the median motor latency was encountered in any group. No association was discovered for sensory latencies for men or for the left hands of women. A small association was discovered for the sensory latency in right hands of long-term female employees. This was similar in magnitude to the increased risk of prolongation associated with aging. Our data provide very little evidence for the concept of cumulative trauma as a prominent cause of carpal tunnel syndrome in American industry. These results are discussed in light of the recent Australian false epidemic of repetition strain injury.