In vivo identification of the shoulder joint centre of rotation using a magneto-inertial sensor

The reconstruction of the human movement requiresthedefinitionofamulti-segmentalkinematicmodelofthe locomotorapparatus.Inseveralbiomedicalapplications,eitherfor the purpose of assessment or to implement a rehabilitation intervention,ahighaccuracyandprecisionintheestimationofthejoint parametersdefiningthekinematicmodelisrequired.Inparticular, the spherical joint is commonly employed to model the kinematic behaviour of several human joints. The position of the centre of rotation (CoR) can be obtained according to functional approach which entails the execution and the recording of ad hoc joint motions. In this work, we investigated the accuracy in the invivo estimation of the shoulder joint CoR using a magneto-inertial measurement unit (MIMU). The protocol was analyzed under different experimental conditions (different movement speeds, joint motion types and ranges of motion). Magnetic resonance imaging (MRI) was used as a gold standard.