Fourier M2/Fourier M2 Kids based on force feedback and other core technologies, provides multiple training modes, which meet all assessment and training demands of the patients with upper limb dysfunction from flaccid paralysis phase to recovery stage.Fourier M2/Fourier M2 Kids has therapeutic games that provide real-time trajectory feedback via a monitor, which motivate users to train with more immersion. The training trajectory can be customised by using the ‘teaching mode’ which gives the therapist more flexibility to create the training plan. Fourier M2/Fourier M2 Kids also can evaluate the user’s training outcomes including the movement trajectory, movement velocity, movement torque, range of motion, muscle strength and active-passive ratio.