Upper-Limb Kinematic Variables are correlated with Fugl-Meyer Assessment Sub Scales During a Hand-to-Mouth Functional Task in Post-Stroke Individuals

Background:: Kinematic analysis is increasingly recognized as a sensitive and objective complement to clinical assessment in post-stroke rehabilitation. However, the relationship between specific upper-limb kinematic parameters and the different domains of the Fugl–Meyer Assessment for the Upper Extremity (FMA-UE) remains insufficiently explored, particularly during task-specific functional actions such as hand-to-mouth movements. Methods:: Sixteen individuals in the subacute phase after stroke performed a standardized hand-to-mouth reaching task while upper-limb kinematics were recorded using a 3D motion capture system. Kinematic variables reflecting movement quality, smoothness, efficiency, and coordination were extracted, along with joint range-of-motion (ROM) measures for the shoulder, elbow, wrist, and trunk. Spearman correlations were computed between all variables and the FMA-UE total score and subscale scores. Results:: Movement quality and smoothness variables show the strongest associations with FMA-UE scores, particularly with the coordination/speed subscale (Section D). Trunk anterior displacement and trunk inclination exhibit moderate to strong correlations with clinical impairment, suggesting compensatory recruitment when upper-limb motor control is limited. In contrast, shoulder and elbow ROM do not demonstrate significant associations with FMA-UE scores during this task. Conclusion:: The findings indicate that kinematic measures provide clinically relevant information that complements traditional assessment of upper-limb function after stroke. These results reinforce the value of integrating kinematic analysis with clinical evaluation to obtain a more comprehensive characterization of motor impairment and compensatory strategies during functional movements.