From The Ergoweb® Learning Center

Wrestling With A Bag of Chips

What do wrist pivot, strain gauges and a handful of potato chips have in common? They were all part of a recent study by the University of Nottingham that tested the strength required to open food packages.

Commissioned by England’s Department of Trade Industries (DTI), the study involved 90 participants ages 50 and above, 30 disabled participants, and mock-ups of various plastic food bags including the kind that hold frozen foods, snack foods, and similar grocery items.

According to the report’s author Stuart Smith from the University of Nottingham’s Institute for Occupational Ergonomics, the study was intended to help reduce accidents associated with opening tough packaging.

In an article in the Nottingham Evening Post, Smith noted that elderly consumers can have difficulties opening packages. “A 70-year-old, for example, has the average strength of a ten-year-old and can find these packages quite difficult to manage. They will frequently try slicing across the packets with a kitchen knife to get them open and that is how accidents occur,” Smith was quoted as saying.

In addition to testing the strength required to open a bag of chips, the study found that people naturally attempt to prevent chips from flying out of the bag upon opening by using a wrist pivot action. The study also found that men studied were stronger than women, that older participants were weaker than younger ones, and that larger bags enabled participants to use more force to open the package.

In October, 2002, Ergoweb Inc. reported another food packaging study in The Ergonomics Report regarding lids on jars. Dr. Kwan S. Lee of Hongik University in Seoul, Korea, studied the torque and twisting strength required for an average woman to open a jar. According to Lee’s findings, jar lids were unnecessarily tight and raised concerns about potential injuries including tendonitis or acute muscle tears, as well as the frustration associated with opening overly-tight jars.