When people hear the term electrotherapy they often think of the treatment of writer Janet Frame, or of archaic solutions for hysterical women or those deemed to be "unfortunates" who couldn't be controlled.
But electrotherapy has a much gentler side and has been used as a treatment to relieve pain since ancient Rome.
In AD63, Scribonius Largus, court physician to Claudius Caesar, wrote that his pain was relieved when he accidentally stood on an electric fish at a beach.
He went on to promote placing a black torpedo (electric ray) on the area where a patient was experiencing pain to induce numbness and relieve the pain.
It became a standard treatment for headaches and migraines, and was also sometimes used for epilepsy and other neurological conditions.
More concentrated study into electricity-based therapies developed in the 17th and 18th centuries and various contraptions were created to assist with the delivery of the treatments, but the fish was still used.
Benjamin Franklin even had two sessions of electric fish therapy in the mid-18th century. His sessions improved the pain he was experiencing but also resulted in minor amnesia, which lead him to recommend electric therapy trials on melancholic and "mad" patients who were not responding to other more conventional medicines of the time.
The first recorded modern electrotherapy treatment was given to a patient in 1743.
The process was first used to treat mental illness in 1823-1824 and, at the time, electricity was being utilised in a wide variety of experiments, including the failed attempts at reanimation of deceased criminals.
But macabre experiments aside, electrotherapy was becoming increasingly common in the treatment of pain and other maladies.
From the mid-19th century the focus was shifted to providing more localised treatment, rather than large shocks that affected the whole body.
In 1856 Guillaume Duchenne discovered that an alternating current was better than a direct current as it provided better and more consistent results, and was gentler on the skin as it didn't cause blisters.
Electrotherapy works by interfering with pain signals as they are transmitted to the brain, slowing them down and disrupting them. It also helps to speed up the healing of damaged tissue by causing the muscles to contract, which relaxes muscle spasms and helps to prevent atrophy.
It is still commonly used today in the form of Tens machines and Interferential Treatment. Tens works by attaching sticky pad electrodes to the affected area and sending electrical signals across the skin.
Low frequencies increase the production of endorphins, which naturally relieve pain, and high frequencies stimulate non-pain nerve fibres which send signals to the brain and stop the pain messages from getting through.
Interferential Treatment is when two currents are passed through the skin and cross each other, the interference of which is similar to having low frequency stimulation deep under the skin.
Electrotherapy has also been used in the treatment of various cancers since the 1950s.
Sandi Black is the archivist at Whanganui Regional Museum