A handheld system includes a housing, a motion-generating mechanism disposed within the housing, an attachment arm extending from the housing and having a first end coupled to the motion-generating mechanism and a second end configured to receive a user assistive device, a first sensor mounted to measure a first motion of the handheld system and generate a first signal indicative of the first motion, and a control system coupled to the motion-generating mechanism and the first sensor. The control system is configured to use the first signal to stabilize the user-assistive device and compensate for human tremors imparted to the housing.