Electrotherapy is the use of electrical stimulation for therapeutic purposes. Specifically, electrotherapy uses energy waves that are part of the electromagnetic spectrum to produce desired physiological and chemical effects in the body.
Electrotherapy is used to manage both acute and chronic pain. In the gate model of pain, the neural fibers that carry the signal for pain and those that carry the signal for proprioception (body position) are mediated through the same central junction.
Because signal transmission along pain fibers is slower than transmission along proprioception fibers, the gate model suggests that intense stimulation of proprioception fibers can block the slower-moving pain signals.
Some forms of electrotherapy attempt to stimulate these proprioception fibers to reduce the sensation of pain. Other forms of electrotherapy alleviate pain by introducing analgesics and anti-inflammatory medications via electric current to the painful area.
Various types of pain are indications for electrotherapy, including:
Electrotherapy is also used to induce physiological and chemical changes. Some forms of electrotherapy induce these changes by introducing heat into the deep tissues; this deep heating increases blood flow to and from the problematic region and improves drainage. Other forms of electrotherapy are thought to stimulate the body's production of corticosteroids and vitamin D. Still others are believed to promote wound healing by stimulating intracellular activity.
Indications for the forms of electrotherapy that induce physiochemical changes include:
Electrotherapy is used to stimulate the contraction of muscles during rehabilitation. This type of electrical stimulation is used to prevent muscle atrophy and to re-educate muscles after trauma or surgery. This form of electrotherapy can also be used to relieve muscle spasms.
Indications for electrotherapy to stimulate muscle contraction include:
healthy innervated muscle at risk of atrophy from immobilization or injury denervated (lacking natural neural connection) muscle that might atrophy or degenerate low back spasm
Although each modality of electrotherapy has its specific set of contraindications, cardiac pacemakers are a general contraindication for electrotherapy.
Electrical signals from electrotherapy devices can interact with the electrical signals from pacemakers and interfere with pacemaker functioning. Pacemaker disruption is particularly acute with such modalities as diathermy and electrical nerve stimulation.
However, less interference may occur with such radiation modalities as infrared, ultraviolet, and cold laser treatments (these modalities are discussed in detail below in the Description section).
Contraindications for pain relief electrotherapy include:
For the use of electrotherapy to stimulate physiochemical changes, contraindications include:
For the use of electrotherapy to stimulate muscle contraction, contraindications include: