Evaluation of jar lid design characteristics by older women with hand use limitations

The study evaluated several lid design characteristics (diameter, height, top shape, side shape, and surface texture) by means of controlled laboratory testing with older women with hand function limitations. A subjective evaluation process was applied to examine main effects and interactions of lid design characteristics on usability, determined by participants' perceptions of effort and discomfort. Results showed that lid height was the most important design characteristic associated with usability. For 42 mm diameter lids, designs perceived as best were ones with taller height, hexagonal top shape, and convex side shape. For 28 mm diameter lids, the best designs were ones with taller height and hexagonal top shape. Additionally, when the smaller lid's side shape was flat, a serrate surface texture provided some advantages, particularly for subjects with more severe hand dysfunction. This information could be used by package designers to improve jar lid usability for a growing sector of consumers.