These machines accelerate healing in soft tissue injuries. The sophistication of these machines provide the ability to produce many different types of currents that can be applied through a variety of sizes of electrodes . This allows for effective application of different currents dependent on the size of the area being treated and the level of penetration required to best treat a specific soft tissue injury. The machines currents "interfere" with each other in the tissues causing a therapeutic effect. The result is pain inhibition along central and peripheral nerve pathways, muscle stimulation to relieve muscle spasms, and vasodilation of blood vessels to promote increased blood flow which in turn promotes healing.