Assessing Reach-to-Grasp Movements in the Stroke Unit: Validity of an Inertial Sensor-Based Approach

Aim of this study was to develop an anatomical calibration procedure for wearable Magnetic and Inertial Measurement Units to assess Reach-To-Grasp kinematics in the stroke unit. A calliper hosting a MIMU was used to measure the direction of axes identified by pairs of selected Anatomical Landmarks and the inter-ALs distance along these axes. The upper limb was modelled as a two-link open kinematic chain and forward kinematics was used to estimate the position of the end-effector on six subjects wearing three MIMUs on the thorax, upper arm and forearm while performing fifteen RTG cycles. The proposed procedure showed a low bias and good levels of agreement with respect to reference positional data.