I just read a very practical research review article in Ergonomics in Design entitled, “Is Standing the Solution to Sedentary Office Work?” by Jack P. Callaghan, et. al. It provides a suggested ratio of 1:1 alternating between sitting and standing, with no more than 15 minutes of standing at a time. That is good practical guidance supported by a number of research studies.
This is certainly consistent with one of the basic tenets of ergonomics, that frequent re-positioning aids comfort by avoiding repetitive stress or static overload. However, for a typical knowledge worker that computes for six or more hours per day, this means moving between sitting and standing positions 24 times per day.
Is this reasonable? It depends on the desk. When one is using an electric desk, the workflow is interrupted by waiting for the desk to reach the proper ergonomic position to start computing again. An electric desk that takes 20 sec to re-position will waste a total of 8 minutes per day if it is re-positioned according to the guidelines.
In American Journal of Preventative Medicine, an article by Dr. Lucas Carr et al. entitled “Cross-sectional Examination of Long-term Access to Sit–Stand Desks in a Professional Office Setting” observed Swedish call center workers with access to counterbalanced spring or electric hoist sit–stand desks for a longer, albeit unknown, duration, and concluded, “It is possible that use of sit–stand desks declines over time and is dependent upon lift type, as more convenient lifts may translate to greater standing.”
This is one of the main reasons why I believe a counterbalanced workstation (where the weight is supported by a spring lift mechanism), promotes health more effectively than an electric desk. A good counterbalanced desk can be re-positioned virtually instantly, and can be done without disturbing the worker’s thought process. If the worker perceives the effort of re-positioning is too great, they will revert back to sedentary behaviors and begin sitting for longer periods of time, or perhaps standing all the time and experiencing leg or back discomfort.
Wellness experts advise that when you start standing, aim to start in small regular intervals, rather than forcing yourself to stand all day for the first day. The aim should be to get to the point where you can spend half of your working day standing within four weeks. This can be accomplished with a gradually increasing schedule of standing from 10 minutes per hour in Week 1, to 20 minutes each hour in Week 2 and finally 30 minutes per hour by Week 3. If you experience fatigue or discomfort, ease off a bit. A counter-balanced workstation allows the worker to accomplish this, by easily moving as the worker moves. The workstation becomes an extension of the worker, without a lot of thought need to keep it working with them.
Electric desks still excel for very heavy weights, and highly variable loads; however for a normal office worker with dual or triple monitors and normal levels of paperwork, a counterbalanced desk is going to be substantially easier and quicker to lift and lower, and therefore will be more effective promoting comfort. Furthermore, they do not require electrical power, and are quieter.
Some people will continue to sit longer than 15 to 30 minutes. Some will continue to stand more than two to 30 minutes. But whichever position they are in, switching to the next position can be, and should be, instantaneous.
By Pete Segar, CEO, Ergotron Inc., President, Nortek Ergonomics and Productivity Solutions