The nociception flexion (R‐III) reflex: A potentially useful tool in exercise and pain studies

There is a need to better understand relationships between physical activity and pain. Improvements in understanding often stem from methodological advancements. This paper provides an overview of the nociception flexion reflex. The nociception flexion, or R‐III, reflex is a tool that has been fruitfully employed in studies of pain, but has not yet been used much in studies involving physical activity and pain. The methodology of the nociception flexion reflex is described and selected methodological concerns discussed. A brief description of the nociceptive system is included to provide a context for interpreting nociception flexion reflex data. Factors that have been shown empirically to modify the R‐III reflex are summarized. Many of these experiments also provide validity evidence for the reflex as a measure of a portion of the nociceptive system. The relatively few sport, exercise, and physical activity studies that have used the nociception flexion reflex are reviewed. Suggestions are made for future exercise and pain research that might benefit from assessing the nociception flexion reflex