They produced a series of electric shocks, which alleviated pain and helped keep it at bay. For the next 2,000 years, technological advances were scarce and the Torpedo fish remained the preferred vehicle for delivering therapeutic doses of electricity. It wasn't until 1745, and the development of the Leyden Jar, that electrotherapy had its next breakthrough. Physicians now had more control over where, when and how much current they could apply. However, like all new medical technologies, electrotherapy was met with considerable skepticism, and interest in it began to decline toward the end of the century.
Every good idea needs a spark.
By closing the gate, the transmission of pain signals to the brain is stopped. Electricity, they believed, was the key to doing it. Clinical evidence to support their theory was provided in 1967 by Pat Wall and W. Sweet, who reported the success of electrical nerve stimulation for the relief of chronic pain. Initially, electrodes had to be surgically implanted, but it was discovered that current could be sent directly through the skin, eliminating the need for surgery. Electrotherapy's effectiveness in pain relief led to other applications, including rehabilitating injured or diseased muscle and other soft tissue.