While you primarily a keyboard simply for typing—and while a $10 keyboard will type just fine—certain keyboards and set-ups are much better suited for specific tasks and workers. Your keyboard is something you may use all day at your desk, so you should make sure it isn't going to cause you any strain. If you experience any forearm or wrist discomfort or have an MSD (musculoskeletal disorder), considering the type/style of a keyboard being used for the task is crucial because it can promote the use of good postures. If you would like to learn all about setting up ergonomic workstations, we cover this subject and much more in our Office Ergonomics Certification program. Use this as a guidance tool to walk you through some things to consider when selecting and purchasing a new keyboard and explore how to choose & set up the perfect keyboard.
We've all seen those little feet that extend out of our keyboards to create a positive slope angle, but did you ever ask what the real purpose is? The common misconception is that they are for better ergonomics. The truth behind the intent of the keyboard feet is to make it easier to see the keys. Therefore, if the keyboard user is a touch typist (type without looking at the keyboard); or a peck typist (must look at the keys when typing). The advantage of extended feet for peck typists is that they can see the keys more easily. However, using the extended feet also comes at a cost for the wrist because it forces the wrist into a sustained extension posture (wrist angled backward). Therefore, it is best ergonomic practice to retract the keyboard feet to allow the keyboard to lay flat. In fact, there have been various studies that have demonstrated a beneficial effect when angling the keyboard away from the user (with a negative slope) because it promotes a more neutral wrist posture.
So how do we overcome the wrist posture for a peck typist? Try raising the height of the keyboard opposed the using the extended feet on the flat surface. When raising the height of the keyboard, ideally we want it to be in our neutral field of vision therefore not requiring neck flexion to look at the keyboard, but rather just eyes shifting down. The neutral field of vision reaches to 30 degrees below the horizontal line of sight. In raising the keyboard, it is important to ensure that the arms are supported by either the chair armrests or desk and cushioned to eliminate contact stress. Intermittent 20-second breaks from this posture are recommended to allow the worker to lower arms to the side and shake them to promote blood flow to the hands.
The palm rest, or commonly referred to as a wrist rest, is a cushion that is placed in front of the length of the keyboard. Perhaps they are often called a wrist rest because one of the purposes they serve is to raise the height of the wrists while typing, promoting a more neutral wrist posture. However, if the recommendations provided above regarding the use of a flat or negative keyboard tilt are used, the wrists will be neutral. In the case where a palm rest is used, it is important to consider that it is meant for the palm, not the wrist.
When placing the wrist on the cushion, though soft, it creates localized and direct pressure on the nerves and tendons that run through the carpal tunnel of the wrist. Placing this contact stress on the wrist in general, let alone while typing increases the risk of the worker developing an MSD, specifically carpal tunnel syndrome or tendonitis symptoms. Placing the palm on the cushion does not pose any harm or risk because this ‘meaty' muscle part of the hand protects the nerves and tendons from direct pressure.
A number pad may be an important component of the keyboard for certain jobs including accounting, payroll, data entry, etc. that requires the use the number pad consistently throughout the day. The main ergonomic disadvantage of having a keyboard number pad is the distance it creates and forces the hand/forearm/shoulder to move in order to utilize the mouse. If switching back and forth between the keyboard letters, numbers, and mouse is a regular/repetitive occurrence, this could aggravate the shoulder or elbow from the shoulder abduction and elbow rotation. Given that about 90% of people are right-handed and therefore typically use their right hand when using both the number pad and mouse, this creates a high frequency of repetition to reach for the mouse.
In the case where the worker uses the number pad regularly, it would be good to consider either moving the mouse to the left side of the keyboard to use with the left hand or move the number pad to the left side to use with the left hand. This will help distribute the repetitive load on the right hand/elbow/shoulder. Three ways to distribute this load is by using a keyboard without a number pad and placing an external number pad to the left side, or use a keyboard with a number pad designed onto the left side of the keyboard, or keep the keyboard with a number pad on the right side but cover it with a mouse bridge or similar to place the mouse on and use an external number pad for the left side.
For workers who hardly ever use the number pad and can get away with just using the numbers along the top of the keyboard, it would be best to consider a keyboard without a number pad. Alternatively, if one cannot purchase a different keyboard, a mouse bridge would work just as good to bring the mouse closer.
There are also keyboards with a mouse touchpad on the side. This is a great concept because it contains the mouse to a single location, preventing the repetitive wrist ulnar and radial deviations (wrist side bending) associated with using a standard mouse, as well as reduces elbow rotation and shoulder abduction in reaching for the mouse. The touchpad also allows some variability in the muscles used including using the ring, middle, and index fingers. This is a good alternative keyboard solution.
The alternative shaped keyboards primary goal is to address the target postures of wrist deviation and forearm pronation (palms facing down). Keyboards that are partially split (split keys) are designed specifically to reduce wrist deviations by allowing the allowing the wrists to remain aligned with the forearm when using the keys. The full split angled/tented keyboard provides additional benefits by placing the keys on a vertical slope encouraging a more neutral forearm posture. A palm/forearm rest/support needs to be reshaped to fit an unusual vertical angle of the keyboard. A drawback to these types of keyboards is that they are not ideal for peck typists who have to look at keys when typing. These keyboards would result in significant neck rotation and bending for peck typists which may result in other discomforts. For a deep exploration of ergonomic concepts, consider taking our full Certified Ergonomic Specialist course, the gold standard in ergonomic training.
Feel of the Keys
Some keyboards have more traditional raised keys, though laptop-style keyboards are becoming very popular for desktops. Mechanical keyboards have also become very popular, that is, keyboards with a mechanical spring inside instead of a rubber dome. These keyboards have a bit more resistance to the keys. It takes a bit more effort to press them down, and they’ll spring up faster, but overall they have a better and more consistent “feel” to the keys. They don’t wiggle around like traditional keyboards, and you’re less likely to get one key that sticks down more than the others. They do tend to be a bit louder and more expensive, though, so keep that in mind as you shop.
Wired vs. Wireless
The main draw of wired keyboards is the responsiveness which, depending on the task, may or may not make a difference. The drawback to wired keyboards is that it can restrict the area that it is used in and can pose as a nuisance, getting in the way of documents or other desk items. However, if your keyboard stays in one place most of the time and the wire doesn't get in the way of other elements on the desk, having a wired keyboard is reasonable. There are many more downsides to wireless keyboards: they're more expensive, require batteries and often take up a USB port on your machine (unless they're Bluetooth).
Remember, comfort and health come first. You probably spend lots of time sitting at your desk using the keyboard, so anything that can be done to reduce the risk of injury is worthwhile —the rest is just a matter of convenience.e