CKATool: A clinical kinematic analysis toolbox for upper limb rehabilitation.

This study introduces CKATool, the Clinical Kinematic Analysis Toolbox, a Python-based tool for analyzing upper limb movement using 3D motion tracking data. CKATool implements a comprehensive set of commonly used kinematic metrics in rehabilitation and movement science, organized into six domains: speed, smoothness, efficiency, accuracy, control strategy, and joint range of motion. Each metric is implemented as a separate function, allowing users to easily apply, modify, or extend the analysis based on specific research or clinical needs. CKATool integrates the Rerun platform for fast, interactive 3D visualization of joint trajectories and metric outcomes. The toolbox was evaluated using three publicly available datasets: Arm-CODA, 3D-ARM-Gaze, and IntelliRehabDS, spanning both structured and naturalistic upper limb tasks. CKATool successfully processed and visualized all datasets, demonstrating its compatibility with different types of experiments and rehabilitation setups. The source code, documentation, and data formatting scripts are freely available to support open and reproducible research.