The primary advantage of an ergonomic keyboard is that it allows the user to maintain a more natural hand and arm position than those demanded by a traditional keyboard, therefore reducing the potential of repetitive-stress injuries. There are many different types of ergonomic keyboards, and each design offers particular advantages for relieving or preventing conditions such as carpal tunnel syndrome.
One of the most common types of ergonomic keyboard is the split keyboard. This design separates the traditional QWERTY layout in the middle, canting each section at an angle. Using a traditional keyboard forces the typist to pull his hands inward and bend his wrists outward to match the angle of the keys, while this ergonomic design keeps wrists straight and offers a much more natural angle for the arms.
Ergonomic keyboards also frequently include wrist rests to maintain good vertical hand position and alternative pointing devices such as touchpads to reduce a user's need to extend his reach to operate a mouse.
Another ergonomic design is the contoured keyboard, which places the keys into two depressions at shoulder width so that the user can keep both arms perpendicular to the body. Another design mounts the keys vertically, allowing the user to type with his hands in a vertical, thumbs-up position to prevent wrist rotation.