IFC is a piece of equipment produces electrical currents (~4000 HZ) that pass through the affected area of the patient. The current tends to penetrate deeper than other electrical modalities and
has a number of physiological effects that have therapeutic value.
The physiological effects include:
- An increase in localized blood flow which can improve healing by reducing swelling (the additional blood flowing through the area takes edematous fluid away with it) and as a result helps remove damaged tissue and bring nutrients necessary for healing to the injured area
- The stimulation of local nerve cells that can have a pain reducing/anaesthetic effect due to potentially blocking the transmission of the pain signals (pain gate mechanism) or by stimulating the release of pain reducing endorphins (opiod mechanism)
- Some degree of muscle stimulation as muscle contraction can be achieved through external application of an electrical current, overcoming some of the muscle inhibition often caused by local injury and swelling
The electrical current is applied to the affected area using four electrodes. The four electrodes are placed in such a way that the two currents produced cross each other in the affected area. For example, if it is a knee injury that is being treated, the two currents can be applied so that they cross deep within the actual knee joint itself. Where the two currents meet, they actually ‘interfere’ with each other; hence the name ‘interferential.’
The patient should not feel any discomfort from the application of the interferential current. The electrodes will usually be used with sticky pads or a damp sponge placed between the electrode and the patient’s skin.
If discomfort is felt it is usually because:
- A sticky pad is old
- A sticky pad is not properly cleaned
- An electrode sponge is not damp enough
- An electoode sponge is not entirely covering the electrode and therefore is allowing some direct contact between a portion of the electrode and the skin.
During treatment patient will feel a tingling or ‘pins and needles’ sensation at the area being treated. This sensation may continue for a brief period following treatment as well. The intensity of the current should be increased within the patient’s comfort level. A stronger current will usually have a more beneficial effect but the intensity should not be turned up so high as to cause pain.