An evaluation of modern day kitchen knives: an ergonomic and biomechanical approach
The focus of this study was to evaluate how different knife characteristics affect the consumer's ability to slice vegetables. There are many variables to a knife and there are beliefs about what makes for a better knife. There are two common multipurpose knives used for slicing vegetables, the chef knife and the santoku knife. The aim of the first portion of the study was to investigate if there is a difference in cutting between a chef knife and a santoku knife, a ceramic knife and a stainless steel knife, and a sharp and dull knife in terms of muscle activation, body part discomfort, time, and slice performance. In order to test these variables, four different knives were used. 50 participants sliced two pounds of vegetables with two knives each, each on a different day. The results show that for the consumer, the type of knife, material, and level of sharpness do not affect the user's muscle activation, discomfort, time, or slice performance. In the second portion of the study the Pinch Cinch grip was designed to be placed on the knife to create an affordance for users to hold the knife in a pinch grip. This grip aligns the wrist and forearm and decreases fatigue and increases stability and control while cutting. The designed grip, the Pinch Cinch, is to be used as a training mechanism for the consumer to easily adjust to using the pinch grip. The grip was tested with 16 participants against a previously tested knife to ensure it did not require more muscle activation, time, discomfort, or cause lower slice performance. The results showed this grip did not have any significant difference from the knife with out the grip. The Pinch Cinch did not have any negative effect on the task compares to the other knife tested. The Pinch Cinch can ensure the consumer is maintaining the pinch grip, and allows them to become accustomed to it by having the affordance present. With the use of the Pinch Cinch, the consumer will feel the pinch grip is natural and retain the benefits of more control and stability.