A system for measuring an inputting range of motion data to a computer comprises a goniometer for measuring range of motion and for producing a range of motion signal from those measurements. A plurality of switches are carried by the goniometer for producing control signals. An interface device receives the range of motion signal and digitizes that signal to produce range of motion data. The interface device also receives the control signals which are used to control the input of the range of motion data to the computer.
