Electrical stimulation is the application of an electrical current to the human body via electrodes from a box. There are two major therapeutic purposes for using electrical stimulation: muscle activation and pain management.

There is a multitude of different kinds of electrical stimulation units that come in different sizes geared for different purposes. Despite the elaborate claims and advertisements, electrical stim is fairly simple. It consists of a set of pads that delivers an electrical current to the body. This current has a shape or wave to it.

The frequency of how many waves occur in a second is one of the main controlling outputs. A frequency of 20-50 pulses per seconds or HZ will stimulate the nerve to contract the muscle. Higher or lower frequencies do not produce true muscle contractions  but will stimulate the nerves to interrupt pain messages .

There are other aspects of how the pulse is delivered and what shape the pulse takes that can influence how the treatment feels.

When there is a problem in the body, the nerves in the area send pain messages to the brain. These messages are delivered until the problem goes away. Sometimes it takes a while for the problem to resolve which results in a chronic pain situation. The sensation of electrical current will interrupt this persistent pain message which gives the brain a break. Interrupting the message helps relax the muscles in the area which have tensed up as well as restore local circulation. Research has also been able to show that these levels of pulse frequencies will stimulate the production of enkephalins which are the body’s natural pain killers.

Muscle activation and strength training

This application of electrical stim gets a lot of advertising attention. Developing bulging strong muscles by simply applying electrodes and avoiding the work and sweat is appealing but unrealistic. There is research that supports the development of muscle function with electrical stim; however, there are specific circumstances in which this is helpful.

Every muscle requires a connection with a nerve in order to contract. If the nerve connection has been interrupted then the muscle cannot function. When a muscle hasn’t been used, it starts to atrophy or waste away. Electrical stimulation with the right current settings can fire a muscle contraction and prevent complete atrophy.

Unfortunately there are a lot of diseases and traumas that affect the nerve muscle relationship. Research has shown that electrical stim will help prevent severe strength loss and fire the muscles when the nervous system can't.

There are other situations where the muscle weakness is so severe that the contraction is inefficient and strength exercises are not effective. Application of electrical stimulation can increase the power of the contraction. A muscle contraction stimulates a growth response in the cell of the muscle and connective tissue. The direction, type of contraction, and amount of load on the muscle determines the amount of growth response that will occur. Electrical stimulation has been shown to improve muscle strength in situations where the muscle is profoundly weak or when there is a problem with the nerve. Normal functioning muscles need loads that stress normal capabilities in order to elicit a growth response.