*Article* **The Influence of Di**ff**erent Levels of Cognitive Engagement on the Seated Postural Sway**

### **Daniele Bibbo \*, Silvia Conforto, Maurizio Schmid and Federica Battisti**

Department of Engineering, University of Roma Tre, Via Vito Volterra, 62, 00146 Rome, Italy; silvia.conforto@uniroma3.it (S.C.); maurizio.schmid@uniroma3.it (M.S.); federica.battisti@uniroma3.it (F.B.)

**\*** Correspondence: daniele.bibbo@uniroma3.it; Tel.: +39-06-5733-7298

Received: 5 March 2020; Accepted: 30 March 2020; Published: 31 March 2020

**Abstract:** In this paper, we introduced and tested a new system based on a sensorized seat, to evaluate the sitting dynamics and sway alterations caused by different cognitive engagemen<sup>t</sup> conditions. An office chair was equipped with load cells, and a digital and software interface was developed to extract the Center of Pressure (COP). A population of volunteers was recruited to evaluate alterations to their seated posture when undergoing a test specifically designed to increase the cognitive engagemen<sup>t</sup> and the level of stress. Relevant parameters of postural sway were extracted from the COP data, and significant alterations were found in all of them, highlighting the ability of the system to capture the emergence of a different dynamic behavior in postural control when increasing the complexity of the cognitive engagement. The presented system can thus be used as a valid and reliable instrument to monitor the postural patterns of subjects involved in tasks performed in a seated posture, and this may prove useful for a variety of applications, including those associated with improving the quality of working conditions.

**Keywords:** seated posture; cognitive engagement; stress level; load cells; embedded systems; sensorized seat
