Electrophysical modalities such as ultrasound and interferential therapy have been used in mainstream practice therapeutically since the 19th century. All modalities involve introducing physical energy into your body which results in physiological changes for a beneficial effect. The effects and type of electrophysical modality will be determined by the type of injury, location and desired benefit. It is important to note that whilst electrotherapy modalities have moderate to strong evidence of significant therapeutic effect, they are recommended to be used as an adjunct to other treatments. Your physiotherapist may recommend a type of electrotherapy modality along with some manual therapy and an exercise program for example.
Ultrasound Therapy
Ultrasound creates mechanical sound waves which produce energy and cause oscillations in tissue cells. Ultrasound is a mechanical energy rather than an electrical agent and helps to improve tissue healing and reduce pain. When ultrasound is used, gel is placed onto the applicator head and placed onto the area of injury. The ultrasound operates at a high mechanical frequency which is higher than the normal human sound range to create mechanical vibration. It should be a painless treatment which can be used for many types of presentations, acute or chronic. As with interferential, it can be used to promote tissue healing and decrease pain and can be adjusted for different frequencies and depths for the most beneficial effect.
Interferential Therapy
Interferential utilises low frequency of electrical stimulation of nerves to provide a therapeutic benefit. Your physiotherapist will place 2 or 4 poles onto the area of injury, and apply a sweeping or alternating low frequency electrical stimulation. Research shows there are four main clinical effects of interferential therapy – pain relief, muscle stimulation, local blood flow increases and reduction of oedema. The main effect will be the effects on nerve tissues to reduce pain, the other tissue effects will likely be secondary to this in the local area.
