Posture theory doesn't stand up to scrutiny

A new study casts doubt on whether adopting recommended postures actually reduces or prevents musculoskeletal injuries among computer users. US researchers expected that the study would provide empirical evidence supporting the imple-mentation of ergonomic interventions to prevent upper extremity musculoskeletal disorders (UEMSDs), noting that little had been published on the topic.

They divided into three groups 376 workers who used a computer for more than 15 hours a week. One group received a conventional intervention (ergonomic recommendations from a number of sources including America's NIOSH) while another received an alter-native intervention based on protective factors for musculoskeletal symptoms identified in an earlier study. The third group received no intervention.

The workers' neck/shoulder symptoms and hand/arm symptoms were monitored over six months, and the researchers observed no significant difference in the incidence of symptoms across groups.

They say the study provides no empirical evidence for recommendation of one posture over another for preventing MSDs among computer users.

This may be due to an ability to ensure workers were fully compliant with the interventions (although the majority of both intervention groups were able to achieve substantial, if not full compliance), and they suggest caution should be exercised when making recommendations regarding posture as the sole means of minimising risk of musculoskeletal symptoms among computer users.

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