Since the computer mouse is a fairly new development, most computer workstations were built before it was in use. When the mouse came along, it was usually positioned in the only spot where there was room: the top right of the desk, beside the keyboard (Figure 1).

This was not the easiest place to reach, however. Having 'extra keys' to the right of the commonly-used letter and number keys (for example, arrow keys, insert, page down and the number pad) do not allow users to place the mouse more directly in line with their arm and shoulder. As the use of mice became more and more common, more and more people began to complain of discomfort, aches, and pains in the neck and shoulder area, and along the whole arm with which they used the mouse. Reaching your arm forwards beyond an "easy reach" zone can lead to these discomfort and even injury. (For more on this, please see the OSH Answers document "Computer Mouse: What Kind of Problems Can it Cause?").

A typical computer workstation (Figure 1) does not have enough space to properly position a mouse, but a space must be made so that the workstation is safe and comfortable. One way to make this space is by using a mouse platform. Another way to make this space is by using a shorter keyboard (for example, one without a number pad).

When there is not enough space on the desk to position a mouse within easy reach, you can use a mouse platform. A mouse platform covers the numerical pad on the right side of the keyboard - which is rarely used in many office functions - and serves as a place for the mouse to sit. (Figure 2). The mouse is then closer to the person using it. As well, because the mouse is on a platform, you avoid the tendency to wiggle it further and further away, which would make you reach even further and cause muscle strain.

However, the height of the mouse platform puts your hand in a slightly unnatural position. To make using it more comfortable, you can use a forearm support. (Figure 3).

Advantages of a mouse platform:

• Reduces sideways and forward reaching.
• Reduces the overall area in which you use the mouse.

Disadvantages of a mouse platform:

• The platform raises the mouse a little above the keyboard. Using a slightly higher arm support with the platform can position your hand more naturally.

Computer keyboards come in many sizes. By using a shorter (14" long) keyboard instead of a regular (18" long) one, you will have 4 extra inches of space at the side of the keyboard where the mouse can be placed (Figure 4).

Advantages of a shorter keyboard:

• The extra 4 inches gained by using a shorter keyboard will make you have to reach sideways much less.
• Fewer sideways movements mean you will be more comfortable and less likely to get injured.

Disadvantages of a shorter keyboard:

• A shorter keyboard means you have to get used to a slightly different key arrangement. However, most people don't mind this as long as using the mouse becomes more comfortable.

Note: Whatever shape, size, or application of mouse you use, a battery-powered cordless mouse is highly recommended. It eliminates one of the most common problems with using a mouse: the cord getting stuck or in the way.