eyes on screen or copy

wrists straight elbows to your side

feet flat

back straight

rear endat the backof the seat

Hands, wrists, and forearms are straight, in-line.

Head is level, or bent slightly forward, forward facing, and balanced.

Shoulders are relaxed and upper arms hang.

Elbows stay in close to the bodyFeet flat on the floor or foot booster

Back is fully supported by back of chair

Thighs and hips are supported by a well-padded seat and generally parallel to the floor.

http://www.osha.gov/SLTC/etools/computerworkstations/index.html#