**4. Conclusions**

In this paper, a new system to assess if engaging cognitive activities influence the postural sway of a subject seated on a chair is presented. The designed and realized system, based on a chair equipped with force sensors that allows the dynamics description of the examined motor act, provides the time trend of the volunteers' position. These data can provide useful information on the adopted strategies in the seated postural control in subjects directed towards a complex cognitive task in a reduced amount of time. The obtained results show a significant difference in sway strategy and a coherent variation for a high number of examined volunteers, thus supporting the hypothesis that the higher demand the cognitive task has, the lower the stability in the seated posture. The realized system is

based on the integration of sensors on a normal o ffice chair, whose physical features are not modified. Moreover, the system is designed to be powered with batteries and can be improved by embedding a wireless transmission. All these features allow the use of the chair in a wide range of situations, such as a smart working environment, where the device can provide useful information about the risk related to working activities due to the task-induced cognitive load.

As a future development, the system could be further validated by using additional techniques for cognitive load assessment, such as EEG analysis, testing the same setup in conditions similar to the ones presented in this work.

The realized device will be completed with seat backrest sensing, in order to obtain a system that allows a complete analysis of the adopted posture. This can be very useful to monitor activities that require a prolonged seated time, and where the cognitive engagemen<sup>t</sup> is constant: in this case, the postural sway could be a useful indicator of global fatigue, thus giving important information on the correct time schedule of the performed working tasks and to prevent all the pathologies related to the adoption of improper seated postures.

**Author Contributions:** Conceptualization, D.B. and F.B.; methodology, D.B., S.C., and F.B.; software, D.B. and F.B.; validation, D.B., and S.C.; formal analysis, D.B. and F.B.; investigation D.B., M.S., and F.B.; resources, S.C. and M.S.; writing—original draft preparation, D.B. and F.B.; writing—review and editing, D.B., S.C., M.S. and F.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** The authors would like to thank Moses Mariajoseph, Giorgio Scordino and Arturo Zezza for their contribution in recruiting the volunteers for the experimental campaign.

**Conflicts of Interest:** The authors declare no conflict of interest.
