mmPhysio: Millimetre-Wave Radar for Precise Hop Assessment

Motion tests for physiotherapy purposes are a cornerstone in a rehabilitation process. For many reasons, clinicians have been manually measuring and tracking movements so far, being subject to inaccuracies and increasing the time spent in those assessments. This paper studies the reliability of a millimetre wave (mmWave) radar to perform motion tracking for accurate hop tests. Once the variables of interest are extracted and the system set up, the results demonstrate that this system's accuracy allows its use in clinical environments, facilitating the task of tracking motion and extracting the distance covered by the subject when hopping. The radar outputs are compared against a well-known marker-based optical system, showing high agreement and validating the radar's effectiveness, with a difference of less 8 cm in the single hop test, 10 cm in the triple hop test, and 21 cm in the crossover hop test for 75% of all measurements. Hence, this approach offers a contactless, efficient, and precise alternative for physiotherapy motion assessment.