The handling of consumer packaging.
Measurements have been made of the comfortable and maximum torques and compressive forces which people can exert when opening jars, bottles and cardboard cartons. Dummy containers, specially instrumented with strain gauges, were used for the purpose. Samples were obtained of both the 'normal' and the disabled populations, the latter covering a range of disabilities and degrees of handicap. On the basis of the torques and forces that could be exerted comfortably by 95% of the 'normal' sample, and at maximum strength by almost all of them, possible norms for the required opening forces have been recommended. For jars, these norms are well below the torques actually required to open present-day containers. It was not considered feasible to suggest norms for the disabled population, but rather to recommend the development of aids to help them open containers. It has been shown that there is some constancy in the ratios of torques between sample percentiles (for example [Formula: see text] ile) between men and women and between the maximum and comfortable torques, across all the jars and bottles used. This has implications for sample size and composition in future studies.
Berns
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Ergolab, Renstiernas gata 12, S-116 31, Stockholm, Sweden.