Transcutaneous Electrical Stimulation (TENS) has a pain killer affect similar to narcotic analgesics. TENS, vacuum interpherential current and other electrotherapy modalities may have anti edema, vasostimulation, anti inflamation affects according to duration, amplitude and type of the current. Ultrasound is a high frequency sound wave therapy modality that has non thermal and thermal affects. It increases blood flow and stimulates production of collagen.
