Stroke-affected upper extremity movement assessment via continuous relative phase analysis

Paper presents the quantified assessment of stroke-affected upper extremity (UE) coordination via continuous relative phase (CRP) analysis. 14 post-stroke patients were divided into 3 groups based on the severity of impairment according to Wolf Motor Function Test (WMFT). CRP was determined based on UE kinematics parameters measured using inertial measurement units fixed on arm, forearm and hand while subjects performed designated movement. UE movement cycles were analysed based on the metrics derived from phase planes, the phase angle and CRP plots, as well as the calculated range of motions and CRP variability rates. It was found that CRP variability is associated with impairment level, i.e. it is decreasing with a higher level of dysfunction. Therefore, the CRP might serve as measurable quantity and could be valuable for supporting clinical assessment and quantifying impairment severity of UE motor functions.