Taking the pain out of shots

Such painless injections could be possible with a device that applies pressure and vibration while the needle is inserted in the skin, according to a study presented at the Anesthesiology 2014 annual meeting. As many as 1 in 10 people experience needle phobia. Using a device that applies pressure and vibration before the needle stick could help significantly decrease painful sensations by closing the 'gate' that sends pain signals to the brain.

The perception of pain was significantly decreased when a specific amount of pressure and vibration was applied to the site for 20 seconds prior to using the plastic needle. The addition of heat added a small benefit. 

The concept likely works by distraction as well as employing the gate-control theory of pain, in which these sensations (pressure, vibration and potentially temperature) close the gate that allows the brain to register pain.