Economy - Etymology. 1  The English words economy and economics can be traced back to the Greek word Î¿á¼°ÎºÎ¿Î½ÏÎ¼Î¿Ï (i.e. household management), a composite word derived from Î¿á¼¶ÎºÎ¿Ï (house;household;home) and Î½Î­Î¼Ï (manage; distribute;to deal out;dispense) by way of Î¿á¼°ÎºÎ¿Î½Î¿Î¼Î¯Î± (household management).
Today many people confuse TENS with electrical muscle stimulation (EMS). EMS and TENS devices look similar, with both using long electric lead wires and electrodes. TENS is for blocking pain, where EMS is for stimulating muscles.
TENS vs EMS: the main difference between the two: 1  TENS stimulates the nerves â the rationale being that the simulation keeps pain signals from reaching the brain.  EMS causes the muscles to contract â by mimicking the action potential that comes from the central nervous system.