Development of Wearable Posture Identification System for Object Lifting

The development of wearable technology for posture monitoring has become increasingly important in preventing work-related musculoskeletal disorders, particularly in manual material handling tasks. This project presents the development of a wearable posture identification system designed to monitor trunk angles during safe lifting activities, with the aim of preventing unsafe lifting postures that could lead to back injuries. The system utilizes an MPU9250 inertial measurement unit for angle detection, integrated with an ESP32 microcontroller for processing, and a buzzer for real-time feedback. The components are housed in a 3D-printed case mounted on a neoprene waist support, creating a comfortable and practical wearable device. The system is programmed to alert users when their trunk angle exceeds 60 degrees during lifting activities, as recommended by ergonomic guidelines. Calibration testing demonstrated the system's measurement accuracy, with percentage errors ranging from 7 % at lower angles to 0 % at 90 degrees, showing particularly high accuracy in the critical range above 45 degrees. Repeatability testing conducted with three subjects of different heights $({1. 7 3\mathrm{m}}$, $1.70\ \mathrm{m}, 1.68\ \mathrm{m}$) confirmed the system's consistency in measuring spine angles during standardized lifting movements. The results indicate that the developed system successfully provides reliable posture monitoring during lifting activities, offering a practical solution for workplace safety. The integration of accurate measurement capabilities with a wearable design makes it a viable tool for presenting unsafe lifting postures in real-world applications.