Fig. 7

(Up) Upper limb joints angles estimated through the proposed algorithm (blue line) and with the previous algorithm (red dotted line). The gray area denote the instability of the previous algorithm, i.e. the time in which the upper limb joints cannot be estimated with the previous algorithm. In these areas the arm joints were set to the last known value estimated through the previous algorithm. (Middle) Shoulder displacement performed during the therapy by the patients. The red line is the right(+)/left(-) movement, the green line is the forward(+)/backward(-) movement and the blue line means the up(+)/down(-) movement. (Down) Trajectory performed during the therapy with the end effector of the robot (blue line). The red circles are the goals of the roulette exercise