Pain stimulus is a technique used by medical personnel for assessing the consciousness level of a person who is not responding to normal interaction, voice commands or gentle physical stimuli (such as shaking of the shoulders). It forms one part of a number of neurological assessments, including the first aid based AVPU scale and the more medically based Glasgow Coma Scale. Pain stimulus is a technique used by medical personnel for assessing the consciousness level of a person who is not responding to normal interaction, voice commands or gentle physical stimuli (such as shaking of the shoulders). It forms one part of a number of neurological assessments, including the first aid based AVPU scale and the more medically based Glasgow Coma Scale.