Wearables in the Drop Zone: Human-Centered Design of a Sensor Sock for Airborne Training

Military airborne training exposes soldiers to high biomechanical loads during parachute landing falls (PLFs), contributing to persistent lower-extremity injury risk. While ankle braces exist that reduce injury, operational adoption is very low. This paper presents a human-centered design case study focused on the development of a wearable sensor sock for assessing PLF biomechanics and supporting training evaluation. Stakeholder engagement, operational site visits, and laboratory testing were used to iteratively refine the wearable system’s sensing strategy, wearability, and integration within existing training workflows. The prototype integrated force sensing resistors, inertial measurement units, strain sensors, and electromyography sensors to measure plantar loading, landing impact characteristics, ankle kinematics, and lower-leg muscle activation patterns relevant to PLF performance. Key lessons learned highlight the importance of designing wearable systems that align with user culture, instructional practice, and the realities of field deployment.