Design and Validation of a Pressure-Based Insole for the Quantitative Assessment of Gait Abnormalities

This study presents the design and validation of a wearable in-shoe system for real-time monitoring and quantitative analysis of plantar pressure distribution during walking. The system incorporates ten force-sensitive resistor (FSR) sensors strategically placed at key anatomical regions of each foot, enabling high-resolution pressure mapping. Data acquisition and wireless transmission are managed via an ESP۳۲ microcontroller using TCP/IP protocol, with onboard microSD storage for redundancy. A custom graphical user interface (GUI), developed in Delphi, enables live visualization and recording. It also supports signal processing techniques, including dynamic time warping (DTW) for temporal alignment and signal averaging for noise reduction. Experimental trials were conducted on four adult participants (aged ۲۲–۴۵), including one individual with a normal gait and three with abnormal patterns, such as internal rotation, external rotation, and supination. Each participant completed multiple walking trials on a treadmill at a constant speed for a duration of ۱ minute under standardized footwear conditions. The results confirmed that the system achieved high accuracy in distinguishing gait abnormalities, validated through quantitative metrics and visual pressure profiles. The proposed system provides a low-cost, portable, and clinically relevant solution for early detection of gait disorders and long-term rehabilitation monitoring. Its modular architecture and real-time performance demonstrate its potential as an effective tool for both clinical and remote rehabilitation monitoring.

Keywords:

Biomechanics , DTW , FSR sensor , Gait Analysis , Plantar Pressure Distribution , Postural Disorders , Rehabilitation Monitoring , Wearable Systems , Wireless Sensor Networks , Motion Impairment Detection