Integration of Wearable Inertial Sensors and Mobile Technology for Outpatient Functional Assessment: A Paradigmatic Application to Evaluate Shoulder Stability

Wearable devices based on inertial measurement units (IMUs) are now-a-days a de facto standard in the field of human motion analysis. Lower costs, improved quality and enhanced accuracy promote a very fast and diffused adoption of such devices in healthcare and wellness areas. In clinical settings, these technological solutions allow for a quantitative evaluation of functional and clinical tests. This article aimed to present a practical and feasible approach using IMU-based wearable devices and mobile applications to rapidly collect 3D motion information coming from different body segments. The proposed solution was specifically designed for a rapid and precise monitoring of the patient’s status both outdoor and indoor, including home and clinical contexts. The modularity concept in designing the application allows to easily plug specific and customized modules addressing data analysis and patient status assessment. The acquired data are always available to the user to be archived or re-processed. Without loss of generality, the developed system was tested in a real clinical context, addressing the need for assessing the shoulder mobility in order to automatically identify the presence of symptomatic or asymptomatic humerus-scapular dyskinesis. This approach allowed to define a kinematic-based set of novels metrics - called Shoulder Primary Key Indicators. The proposed system demonstrated to be a practical and effective solution in the most clinical context, giving room to the adoption of this kind of approach to a wider range of applications related to the functional assessment of different body segments and joints, such as the knee, the spine or the elbow.