Real-time smoothness-based assistance during rhythmic arm movements

Rhythmic and discrete movements are two fundamental motor primitives being - at least partially - controlled by different neural pathways. After a stroke, both primitives can be impaired. However, current upper-limb therapies - both conventional and robot-assisted - train mainly discrete functional movements. In order to recover the complete motor repertoire, training both movements should be offered with dedicated exercises. The paper elaborates a new performance-based robotic assistance to train rhythmic movements with a rehabilitation robot. More precisely, it develops and validates a performance-based smoothness assistance. The developed assistance aims at smoothing the movement being performed, based on a real-time estimate of the movement smoothness.