Different frequencies of the interferential current can stimulate different nerve pathways to affect the pain gate and the opiod system to help reduce pain. Stimulation of the the motor nerves which make the muscles contract, at a wide range of specific frequencies, will relax muscle spasm, stimulate weak muscles which in turn increases blood flow, aids healing and reduces swelling. By simulating the parasympathetic nerve fibres there is also an increase in circulation.
Depending on the symptoms needing treatment the appropriate frequencies are selected. It is particularly useful to treat joints as it penetrates into the joint and therefore is a deeper treatment compared with other techniques.