Another necessary feature is having a full size work surface. To stand a substantial portion of the day, the normal desk items must be available at both the standing and sitting positions. These include not just a keyboard and mouse, but many other items such as work papers, files, phone, stapler, tape dispenser, calculator, etc.
An important, but seldom discussed or thought about factor is lean-ability. Adjustable height desks MUST be designed for the user to "lean on". Without the ability to occasionally offset part of your weight onto the desk from different angles and positions, you will quickly tire and will end up sitting most of the time. Test this for yourself. Stand in a static, vertical position with your forearms extended as if typing and see how long you last. Gravity will quickly stress your back, arms and legs. Lean-ability involves more than just sturdiness, but design as well. One major national call center spent a great deal of money providing elaborate electric adjustable height desks for all their employees only to find that at any given time less than 2% were standing (they had expected 50%). Why? The desks were designed with a separate adjustable front keyboard tray which facilitated a comfortable, reclined sitting position. But when standing it was awkward to lean on. So rather than strengthening their core muscles and gaining the many other health benefits of standing, employees sat almost all the time in an unhealthy semi-reclined position.
The final crucial feature of a quality sit and stand desk is having a separate level for the monitor. A separate adjustable rear monitor shelf or a moveable monitor arm is necessary to provide a custom height placement of the monitor that is separate from the front work surface. Many users find that when standing (and leaning), the monitor screen is viewed most naturally at a level just below the work surface so the neck is not craned upward. In order to position the viewable part of the monitor screen at or just below the work surface, the monitor itself must often be placed 4 to 8 inches lower to offset the height of the monitor base. Conversely, in a sitting position, when leaning against the back of the chair, a higher monitor position provides a more natural view angle.
Only one desk on the market today combines all of these features into an adjustable height desk that is affordable for companies to stock their desks with. The Desktop Elevator, by OiC Innovations, is that desk. Check it out at http://desktopelevator.com today to order and get on board with the sit to stand revolution!