FACT SHEET: Proper Wii Remote Usage

Nintendo is continuing a dialogue with its customers about the proper and safe use of the motion-sensitive Wii Remote controller when playing Wii Sports.

The following tips are advised for safe play:

Always wear the wrist strap while playing.
Keep a firm grip on the Wii Remote at all times.
Make sure people and objects are out of the range of movement before play begins.

More tips at source.