# Sitting Posture Recognition Systems: Comprehensive Literature Review and Analysis
## 3 Sensing Technologies  
Researchers have put forth several solutions to tackle the challenge of posture recognition. The crux of such systems lies in the sensing devices. The existing literature on sitting posture recognition systems classifies them into various categories based on the type of sensor used. To achieve accurate and reliable monitoring of sitting posture, sensors must surround users to capture the relevant features. Sitting posture recognition typically employs a variety of sensors to capture and analyze body positions. Commonly utilized sensors for this purpose include pressure sensors, flex sensors, accelerometers, gyroscopes, inertial measurement units, strain gauges, and ultrasonic sensors. The pressure sensors offer seamless integration into office environments, such as chairs or desks, enabling non-intrusive monitoring of sitting postures without the need for users to wear any devices. This approach strikes a balance between accuracy and convenience, allowing for continuous and unobtrusive monitoring of sitting postures without compromising user comfort. Strategically positioned pressure sensors in the office environment can seamlessly collect pertinent data concerning ergonomics and sitting posture, all without disrupting the user's \begin{table}
\begin{tabular}{c c} \hline \hline
**Journal** & **Articles** \\ \hline Sensors & 16 \\ IEEE Sensors Journal & 4 \\ Sensors and Actuators A: Physical & 4 \\ International Journal of Distributed Sensor Networks & 2 \\ IEEE Internet of Things Journal & 2 \\ IEEE Transactions on Biomedical Engineering & 2 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Article classification by journal. Figure 1: Breakdown of publication based on year. natural movements or activities. The taxonomy of sensors used in the existing research is provided in Table 3.  
Table 4 below presents the comparison of different sensing technologies used in posture recognition applications, briefly providing their functionality, strengths, and limitations. These sensors can be used individually or in combination to enhance the accuracy and reliability of sitting posture recognition systems. The choice of sensors depends on factors such as the desired accuracy, cost, and specific application requirements. \begin{table}
\begin{tabular}{p{42.7 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Sensor Type** & **Function** & **Strengths** & **Limitations** & **Power Consumption** & **Cost** \\ \hline Textile Pressure & Measure the distribution of pressure on the seat and backrest. & Direct measurement of pressure distribution & Limited to pressure points & 1–20 mW [35] & Moderate [36] & Moderate [36] \\ Force Sensors & Detect varying levels of force or pressure. & Measures force or pressure, flexible & Limited sensitivity range, durability & \textless{1 mW [37]} & Low to moderate [38] \& \%7.50–\$12.50 (\$\$\) (Sparkfun) \\ Load Cells & Measure weight or force & Accurate measurement of weight distribution and shifts; robust and reliable. & Bulkier, fixed location & 100–300 mW [39] & Moderate to high [40] \& \textless{564} \\ Flex Sensors & Measure bending & embedded in clothing or other materials & Limited to specific movements & \textless{1 mW [41]} & Low to moderate [42] \& \textless{512} \\ Strain Gauge & Measures deformation & Highly sensitive and can detect minute changes in posture & Robust; used in long-term applications without significant wear & Low to moderate [43] \& & Low to moderate [44] \& \textless{12-65} \\ Inertial Measurement Units (IMUs) & Track movement, orientation, and acceleration of the body. & Dynamic movement acceleration of the body. & Prone to drift, movement tracking, versatile & Prone to drift, sensitive to interference & Moderate to high [45] \& \textless{55.0} \\ RGB Cameras & Capture visual data & Complex posture analysis, non-contact & Requires good lighting, privacy concerns & 200 mW-several watts (W) [47] & Low to high [48] \& \\ \hline \hline \end{tabular}
\end{table}