The influence of acute anxiety on assessment of nociceptive flexion reflex thresholds in healthy young adults.

The nociceptive flexion reflex (NFR) is a polysynaptic withdrawal reflex that occurs in response to painful stimulation. In human studies, NFR responsiveness has been used as a direct measure of nociception as well as an indirect measure of supraspinal modulation of nociceptive transmission. Previous studies have suggested that anxiety may influence NFR responding, and therefore it has been recommended that anxiety be reduced by familiarizing participants with assessment methodology prior to formal NFR assessment.