A recent study indicating that stimulating skin with toothpicks was nearly as effective as puncturing the skin with acupuncture needles is being touted in the medical skeptics circles as proof that acupuncture is some kind of placebo.
There was no sham acupuncture involved. Acupuncture is a technique of stimulating, not puncturing, points on the body for physiological effect. Any kind of acupuncture that touches the skin, including so-called sham acupuncture needles, is acupuncture. The Japanese have developed entire systems of noninvasive acupuncture.
While I am more likely to use a stainless steel probe when I use noninvasive acupuncture techniques, the toothpicks touched the skin at the acupoints. The skin contains three afferent sensory nerves that signal the central nervous system as well as modulating the sympathetic and parasympathetic nervous system, specifically the vagus nerve.
The toothpicks stimulated the cutaneous nerves to send a signal to the spinal cord activating the spinal neurons that secrete enkephalin and dynorphin that inhibit pain messages. Then the signal continued up to the midbrain and pituitary to activate the raphe descending pain-inhibitions system which secretes monoamines, serotonin and norepinephrine. Those further inhibit pain.
Once the sensations from the toothpicks reached the spinal cord several nerve pathways were excited, reaching the cerebral cortex which released neurochemicals that not only inhibit pain but also promotes homeostasis. When the body is in distress, homeostasis does help balance the mind.
The study showed that three techniques of acupuncture beat out western medicine for back pain.