Biofeedback is an approach to revealing the inner states of human functioning so that people can develop control. In pain management it can take many different forms from surface electro-myography (sEMG), skin conductance (SC), blood volume pulsimetry (BVP), respiration rate, and heart rate variability. It can even be as simple as readings on two scales (left foot, right foot); video recording; a mirror; taking your pulse; temperature or weight!
I use biofeedback pretty regularly – so here’s a very quick tour through the biofeedback uses (but wait! there will be more as time goes by…)