Fig. 2From: Performance-based robotic assistance during rhythmic arm exercisesAssistance forces. The three assistance forces that can be provided to the patient to enhance the movement features are presented in the three panels. a The smoothness assistance attracts the patient to the smooth position produced by the adaptive oscillator, b the velocity assistance tangentially supports the patient to reach the desired velocity, and c the amplitude assistance is a radial force towards the desired amplitudeBack to article page