The invention refers to a portable device (100) for upper limb (2, 3) rehabilitation which is movable over a surface, usually a flat horizontal surface, and which comprises means for detecting an intention to move from the user (1), thereby providing assistance/resistance to perform the right movement just when needed, especially when the goal movement is non-deterministic. Additionally, the portable device (100) of the invention comprises a support structure for the forearm of a user (which can be similar to an armrest) which is pivotable, preferably in a direction of the rotational joint of elbow (it pivots vertically around a horizontal axis), thereby allowing free ergonomic elbow and shoulder flexion/extension, but restricting shoulder rotation, which is determined by the orientation of the device in order to avoid injuries. The invention further refers to a method for rehabilitating an upper limb (2, 3) of a user (1), and to a rehabilitation system for an upper limb (2, 3) of a user (1), comprising such portable device (100).
