Electrotherapy is either performed by a physiotherapist or by a trained nurse. It usually lasts a few minutes (up to 20), only the direct current needs a rather long time to act – from 30 to 60 minutes. Electrotherapy may be combined with ultrasound and is most effective if taken in a series of applications. The frequency and length of applications must be prescribed by a physician as well as the precise current type, its application method, etc. Some currents are applied by means of plate electrodes placed in humid protective sheaths onto your skin and fastened with straps, while others are better used with suction-cup, pen-like or button electrodes. The vacuum effect produced by suction cups may alternate so a micro-massage of the underlying tissue improves the circulation and flow of oxygen into it.