Every woman's suspicion has now been proved: no, you're not a weakling, jar lids really are screwed on too tight.
A new Korean study shows that many older women - and a lot of younger people - find opening the lids on a majority of containers beyond their limits.
Scientists at the Hongik University in Seoul, Korea measured the torque required to open the lids of various jars as well as the twisting strengths of young and old women.
Study lead author Dr Kwan Lee has urged food manufacturers to investigate the possibility loosening the jar lids a little. According to the researchers, this would not affect the freshness of the food inside.
Wide lids toughest to screw off
Lee and colleagues tested the lid-twisting strength of 59 women between the ages of 20 and 30, and 50 women in their 60s.
Not surprisingly, they found that younger women had more twisting than older women, although they all struggled to open the containers, Lee reported at the recent annual meeting of the Human Factors and Ergonomics Society in Baltimore, Maryland.
Older women had trouble twisting off 59% of the lids tested. The toughest lids were screw-on jar lids with relatively wide diameters - as opposed to twist-off caps.
Almost 17% of all the women couldn't open a single product with a wide screw-on cap, including 26% of older women.
What worries the researchers about this, is that straining to open a food container has the potential for injury, especially in older women.
Good excuse to visit your neighbour
Acording to Lee, there are no international standards for the torque of product lids. So until there are, the researcher recommend that elderly people ask a strong, young person to open product lids for them. – (Health24)