Reflex loops describe motor or other autonomic output in response to a somatosensory input, such as a mechanical stimulus or acupuncture needle. These loops can be a simple as a two-nerve circuit, such as the patellar reflex. They can also be “long-loop” reflexes- incorporating multiple synapses and input from higher brain centers. One of the homeostatic mechanisms of acupuncture is via reflex modification.
Three examples of long-loop reflexes studied in acupuncture include: finger twitch modification, cardiovascular system modification via the median nerve, and gastro-intestinal modification via the fibular nerve. Reflex loop modification underlies acupuncture effects on autonomic function, as well as providing an avenue for modification of motion related disorders and return to function in a rehabilitation setting.