Good and active sitting

Active sitting is a way of working with an office chair, regularly changing working positions and performing movements that are comparable to the natural movements of walking or standing. Muscles and joints are used in a natural way so that they do not harden and the blood circulation improves. Dynamic office chairs are often used to encourage movement while sitting. This contributes to physical and mental health, as well as longer concentration and better cognitive performance.

Screen work is often an activity that is mainly performed while sitting. Various studies have shown that office workers spend between 65 and 75% of their daily working time (e.g. Parry and Straker, 2013; Clemes et al., 2014). In 2012, a series of articles in The Lancet described physical inactivity as a pandemic and one of the leading causes of previous mortality (Kohl et al., 2012).

Static prolonged sitting is generally considered to be a strain on the mind and body and has been linked to various health problems such as RSI, cardiovascular disease and cancer (Biswas et al., 2015, Kaillings et al. 2021). Muscles and joints are repeatedly and continuously used in the same way over a long period of time (Feveile et al., 2002), resulting in stiff muscles and hardening joints.

On the contrary, the positive effect of physical exercise and exercise on reducing mental stress is widely recognized, and there is evidence that cognitive performance can be improved through exercise (Mualem et al, 2018). Therefore, movement is desirable even while sitting, with movements similar to the natural movements that occur when you walk or stand. The sitting support should therefore have a stimulating effect on active sitting and enable or even provoke changes in working postures. However, there are also times when fully supported sitting can be beneficial, where muscle activity is kept to a minimum with good posture.

A seat angle between the trunk and thighs of more than 90 degrees is experienced as an activating and stretching impulse on the working posture, reducing pressure on the intervertebral discs and improving blood circulation (Nachmenson and Elfstrom 1970, Wilke et al. 1999, Bashir et al., 2006). Depending on the user's tasks and preferences, a good office chair should support good posture and encourage movement in moments of longer than 30 minutes of static sitting periods (Kaillings et al. 2021).

To sit active, choose a chair with a dynamic function or an activating function that triggers you and gives you the possibility to avoid a static sitting position during long periods, as dynamic and activating chairs tend to facilitate movements in static desk-based offices (Colenberg et al., 2021). In this case Float/3D mechanisms or, when no lateral movement is desired, synchro and single point tilt mechanisms can be used.

A higher (open) sitting position, with an angle of more than 90° between torso and thighs will help you to sit straight, move body weight to your thighs and activate the muscles of your legs (Mandal, 1987, Annetts et al., 2012). In this case the depth of your seat should be reduced, or a saddle chair should be chosen to prevent the front edge of the seat of pressing into your thighs while still giving you the necessary support. Furthermore, make sure that you change your working posture regularly “as the best posture, is the next posture”.

Especially, if you want to sit well-supported (often less active) for a certain period, take care that you sit on the very back of your seat and make use of the backrest. Take care that the backrest and lumber support are adjusted in a way that your back is well supported, as this helps you to keep a more neutral position (Cho et al., 2015). Always make sure that you do not hunch forward for a longer period, as such a posture compresses the spinal cord and exerts tremendous pressure on your back (Nachmenson and Elfstrom 1970, Wilke et al. 1999).