This study examines the biomechanics of elbow joint angle variations in recreational downhill sit skiers using motion sensors to enhance adaptive gear development. Inertial measurement units track elbow kinematics across skiing phases - preparation, sustained skiing, and turning - to assess movement efficiency. Findings reveal that recreational sit skiers exhibit variability in elbow flexion-extension across different phases, reflecting adaptations in upper-limb movement patterns to maintain balance, generate propulsion, and adjust to dynamic skiing conditions. Additionally, the study demonstrates that traditional ski gears may restrict upper-limb mobility, especially in high-flexion positions, highlighting the need for ergonomic modifications in adaptive sports gear. By integrating motion sensor data with a human-centered design approach, this research provides a theoretical framework for developing performance-enhancing sports gear tailored to the movement patterns of athletes with disabilities.