Systems and methods for tracking unintentional muscle movements of a user and stabilizing a handheld tool while it is being used by the user are described. The method may include detecting motion of a handle of the handheld tool manipulated by a user while the user is performing a task with a user-assistive device attached to an attachment arm of the handheld tool. Furthermore, the method may include storing the detected motion in a memory of the handheld tool as motion data. The method may also include controlling, based on the motion data, a motion-generating mechanism of the handheld tool that moves the attachment arm relative to the handle in a degree of freedom.