Exercises for rehabilitation and assessment of hand motor function with the Haptic Knob

This paper investigates robot-assisted rehabilitation and assessment of hand function after stroke using the Haptic Knob, a 2 degrees-of-freedom end-effector based robotic device to train grasping and wrist pronation/supination. Nine chronic stroke subjects trained over a period of 6 weeks, with 3 one-hour sessions of robot-assisted therapy per week, consisting in two exercises requiring active participation promoted by therapeutic games. Behavioral data collected by the Haptic Knob were analyzed to evaluate motion control, smoothness and precision over the therapy. Subjects progressively improved their performances in the proposed functional exercises, suggesting improvement in hand motor function. This was confirmed by results of standard clinical assessment as subjects improved a mean of 4.3 points in the Fugl-Meyer assessment scale, accompanied by a decrease in spasticity. These results illustrate the positive effect of therapy with the Haptic Knob and the possibility to use it as an assessment tool to evaluate and monitor hand motor function during rehabilitation therapy.