Nearly all keyboards are the wide 101/2 key type, which force your mouse hand out to the right unless you are left-handed. Unless you do a lot of numeric entry we suggest you choose a narrow 84-key keyboard, perhaps with a separate numeric keypad which you can unplug when you don't need it. They are available through specialist suppliers such as Intolect.

Touch-typists may reduce the risk of carpal tunnel syndrome by using a split angled keyboard like the Microsoft Natural - but it's very wide.

Ideally you should choose a keyboard with keys that just barely support the weight of your fingers, and whose keys don't hit the end of their travel with a harsh stop.

The Schedule to the Display Screen Equipment Regulations which details the minimum requirements for workstations gives the following guidance:

The keyboard shall be tiltable and separate from the screen so as to allow the operator or user to find a comfortable working position avoiding fatigue in the arms or hands.

The space in front of the keyboard shall be sufficient to provide support for the hands and arms of the operator or user.

The keyboard shall have a matt surface to avoid reflective glare.

The arrangement of the keyboard and the characteristics of the keys shall be such as to facilitate the use of the keyboard.

The symbols on the keys shall be adequately contrasted and legible from the design working position.