I sometimes caution about reading too much into recent neurological research claiming all manner of positive physical and medical effects for meditation of all its many kinds. There is a lot of hype that surrounds the topic ...
However, this report seems very common sense.
Grant, J. (2013) “Meditative analgesia: the current state of the field.” Annals of the New York Academy of Science
It is summarized here [my emphasis]
In other words, less focusing, wallowing, judging and other mental narratives which magnify the pain and color the situation.Joshua Grant from the Max Planck Institute for Human Cognitive and Brain Sciences recently reviewed the research on the neuropsychology of meditation and pain. What did he find out? First, that one could compare the efficacy of focused attention (e.g. shamatha, mantra practice, anapanasati) and open monitoring (e.g., vipassana, shikantaza, choiceless awareness, dzogchen) as to their respective abilities to reduce pain, and when one does so, the evidence for open monitoring is much better than that for focused attention. While there’s some evidence that a very skilled yogi practicing focused attention can suppress somatosensory cortical response to pain through a process of distraction, there’s precious little evidence that the average meditator can do so. On the other hand, there’s mounting evidence from three independent laboratories that open monitoring reduces pain sensitivity and related suffering, and does so in a consistent way. Unlike focused attention, open monitoring doesn’t suppress somatosensory cortical responding, but actually enhances it (along with insula and anterior cingulate responding). Instead, it decreases the prefrontal lobe activity associated with elaborative mental processes (e.g., mental narratives, cognitive appraising, and self-involvement) that exacerbate pain. A study of experienced Zen practitioners showed that they exhibited decreased functional connectivity between these brain regions — as if they had developed a way to decouple their sensory perception from their elaborative mental activities — and that the greater the decrease in functional connectivity between these regions, the lower their pain sensitivity.
I once wrote this on similar theme ...
I am afraid that Zazen is not a form of pain management, but it is a total cure for existential "suffering" ("Dukkha" in Buddha-lingo). What is the difference? Well, pain is the physical sensation you feel. However, "suffering" is the self's psychological reaction to the pain which consists of such judgments as "I hate having this pain" "my life now is hopeless because of this illness" "I wish things were some other way" "this is not a good way to be" etc. etc. Pain is condition "Y", your “self” wishes this world to be X, yet this world is not X and is Y instead. The mental state that may result to the “self” from this disparity is Dukkha. I sometimes write ...
Now, I am not saying to just be stoic and "grin and bear" the pain. Sometimes you may need to do so if truly a condition one cannot fix. Then, there is no choice but to fully accept the situation. However, if possible, one can also seek a doctor, a pain management specialist, a hypnotist, various forms of meditation based on directing the mind away from the pain (several have been recommended in this thread and the books mentioned). I sometimes say ...Shakyamuni Buddha gave many examples: sickness (when we do not wish to be sick), old age (when we long for youth), death (if we cling to life), loss of a loved one (as we cannot let go), violated expectations, the failure of happy moments to last (though we wish them to last). Even joyous moments — such as happiness and good news, treasure or pleasant times — can be a source of suffering if we cling to them, if we are attached to those things.
In ancient stories, Dukkha is often compared to a chariot’s or potter’s wheel that will not turn smoothly as it revolves. The opposite, Sukkha, is a wheel that spins smoothly and noiselessly, without resistance as it goes.
Fortunately, Shakyamuni Buddha also provided the Dukkha cure.
What can actually happen is a kind of "acceptance-non-acceptance" all at once. On one level, we do not like it ... seek to fix it. Sure! On the other level, we total embrace and allow the condition, curing the "Dukkha". It is the difference between having pain and concluding "life stinks", and having pain and concluding "well, life still stinks sometimes and I am not always content, but somehow all is also OK, and I am totally Content (Big "C") both with times I am content (small "c") and times I don't feel so content.Zazen is -NOT- a cure for many things ... it will not fix a bad tooth (just allow you to be present with the toothache ... you had better see a dentist, not a Zen teacher), cure cancer (although it may have some healthful effects and make one more attune to the process of chemotherapy and/or dying), etc. Zen practice will not cure your acne on your face, or fix your flat tire. All it will do is let one "be at one, and whole" ... TRULY ONE ... with one's pimples and punctured wheel, accepting and embracing of each, WHOLLY WHOLE with/as each one.
And, although Zazen is not a form of pain management, dropping all the excess focusing, negativity, wallowing, mental judging might actually take our attention away from the pain, make us less prisoners of the pain or even shrink its size as it becomes less important as the central focus of our lives! So, in fact, Zazen may be a kind of pain management technique too!
I hope that Zazen is one step on your dealing with your pain. I know that it will let you be "at home" in your life, even if not completely the home you might wish.