Gripping strategies employed by young children aged 3-5 years when interacting with child-resistant push and turn closures used by pharmacies in the United States.

Abstract Archived video footage from a previous task analysis study where children attempted to open prescription vials outfitted with 42 mm (diameter) push and turn closures was reviewed and grip postures were characterized based on a grip taxonomy presented by Rowson & Yoxall which investigated adult grips (2011). Video review was conducted to identify the types of grip postures children aged 3–5 years utilized when attempting to open continuous thread polypropylene vials outfitted with push and turn, child-resistant closures and compared with grip postures identified with the adults. Children tended to utilize only 3 grip postures (spherical, cylindrical, and pronated cylindrical grips), while adults utilized seven different postures. If children utilize a more limited set of grip postures when opening child resistant closures than their adult counterparts, this difference could be exploited when designing child resistant packaging systems. That said, our study utilized a limited number of CRC designs and confounds existed between the package sizes the children in the archived video footage attempted to open and those that served as the point of comparison which identified grip postures utilized by adults. As such, further investigation is needed across a range of package diameters. Potential implications for child-resistant packaging design are discussed.