Designing, Development and Testing Reliability of Indigenously Developed Wearable IMU System to Measure Joint Kinematics, Center of Pressure and Spatiotemporal Gait Parameters in Normal Human Adults

Background: Quantitative gait analysis is a critical tool for the objective measurement and assessment of human movement, yet it remains underutilized in clinical practice. This method is essential for diagnosing, managing, and treating locomotor impairments. Traditional laboratory equipment, such as optical motion-capture systems and force plates, is often regarded as the gold standard due to its high precision. However, their high costs and lack of portability limit their use in routine clinical settings. This study addresses these limitations by introducing a cost-effective, portable wearable gait analysis system that uses an Inertial Measurement Unit (IMU). The system is designed for versatility, enabling use in both outdoor and indoor environments. Objective: The purpose of this experimental study was to comprehensively evaluate the reliability of the newly indigenously developed wearable IMU system for measuring joint kinematics in the sagittal plane and key spatiotemporal gait parameters in normal human adults. Methods: This study involved a sample of 30 Normal adults (both genders), aged 20 to 45 years, with a body mass index of 18.5 to 24.9 kg/m2. We developed a custom-designed wearable solution comprising an ISM330DHCX IMU, Force Sensitive Resistors (FSRs), a microcontroller, and an Arduino Nano-Raspberry Pi 4. All participants performed a 10-meter walk test, during which the system recorded joint kinematics in the sagittal plane and spatiotemporal gait parameters. Results: The newly developed wearable gait analysis device demonstrated high reliability across most tested parameters, supporting its intended application. The SEM values for the ankle and hip joints in the sagittal plane were below 5 degrees, which is consistent with a clinically acceptable range. On the other hand, the knee joint kinematics exhibited a slightly higher SEM during the mid swing phase (6.7 degrees for the left limb and 6.9 degrees for the right limb). SEM values for all the spatiotemporal parameters, including step length, stance time, swing time, and cadence, ranged from 0.06 to 0.32, demonstrating strong agreement. The mean values of all measured parameters were in accordance with established normative data for a normal human adult population. Conclusion: The results show that the new compact wearable IMU system is a valid and reliable method for quantifying joint kinematics and spatiotemporal gait parameters. With its low measurement error, portability, and affordability, this system is well positioned as an alternative to conventional laboratory equipment. In this context, the potential of quantitative gait analysis is further realized, and its clinical and community applications open new avenues, with the diagnosis, monitoring, and treatment of locomotor deficits potentially assuming a larger role. Keywords: Gait analysis, Wearable sensors, Inertial Measurement Units, Joint Kinematics, Spatiotemporal Gait Parameters, Rehabilitation