Your arm begins to ache, and somewhat burn slightly... Using your arm for any kind of quick movements, or outstretching of the arm generates pain.
You get Wii-arm by playing WiiSports for 14 hours non-stop - Then trying to play Baseball, and finding out that you hit the floor in pain when you swing.
Pronunciation: ‘wE ‘ärm
Function: noun
Etymology: Modern English.
1 : arm and shoulder strain suffered by a new user of Nintendo’s Wii video game system, caused by the multiple and sudden arm movements required to play games on the Wii.