Linear Actuator-based Orthotic System for Elbow Extension and Flexion

This work presents the design, development, and evaluation of an orthotic system for elbow flexion and extension assistance based on linear actuators, intended for individuals with upper limb monoplegia, muscle atrophy, nerve injuries, or neuromuscular disorders. The system is controlled by an Arduino microcontroller and supports both manual and automatic operation modes. A 3D model was developed using Fusion 360, and a working prototype was fabricated to test its functionality. The device offers a range of motion (ROM) from 0° to 90°, with accurate and repeatable control of both flexion and extension. To validate mechanical performance, bench-top tests were conducted, including load, durability, and repeatability assessments. A statistical analysis using linear regression demonstrated a strong positive correlation between load and movement time, confirming the system’s predictable and stable response under increasing loads. These findings indicate that the proposed orthotic device is lightweight (1.5 kg), portable, cost-effective, mechanically robust, and functionally reliable, making it well-suited for rehabilitation applications both at home and in clinical settings.