Many people have a fear of needle injections. Vaccines like the flu shot in the US are given during this season. According to a new study led by the University of California, Irvine, it was found that either a sincere smile or a frown can reduce the pain of a needle injection by as much as 40 percent.
A genuine, or Duchenne smile is the one that elevates the corners of the mouth and creates crow's feet around the eyes. This can significantly reduce the stress and the needle-related physiological response by lowering the heart rate.
Principal investigator Sarah Pressman, UCI professor of psychological science said, "When facing distress or pleasure, humans make remarkably similar facial expressions that involve activation of the eye muscles, lifting of the cheeks and baring of the teeth. We found that these movements, as opposed to a neutral expression, are beneficial in reducing discomfort and stress."
The study included 231 participants who were given an injection of saline by a 25 gauge needle, which is used to give flu shots. The participants self-reported levels of pain, distress and emotion.
The participants held chopsticks in their teeth and were randomly assigned to either express a Duchenne or non-Duchenne smile, a frown or a neutral expression. It was found that in the frown and the Duchenne smile groups, the injection hurt only about half as much as those in the neutral group.
This indicates that these actions make a positive difference in the needle stab experience. Significantly lower heart rates were associated with a sincere Duchene smile.
Pressman said, "Our study demonstrates a simple, free and clinically meaningful method of making the needle injection less awful. Given the numerous anxiety- and pain-provoking situations found in medical practice, we hope that an understanding of how and when smiling and grimacing helps will foster effective pain reduction strategies that result in better patient experiences."