Point stimulation at trigger points or other areas of low impedance are one of the many modalities/pain management techniques that your physical therapist can employ. Unfortunately for us PTs in California, we cannot (yet) utilize dry needling techniques (state laws), so trigger point stimulation is the closest thing we have to dry needling.
Trigger point stimulation is believed to reduce sub-acute and chronic pain via the release of pain reducing peptides called enkephalins. By "altering the brain" of a painful event (ie the trigger point electrical stimulation), we hope to increase systemic circulation of enkephalins - thereby decreasing your pain.
So yes, it is a little bit painful but 100% tolerable! If you've tried this out before let us know how it worked!