A handle used to control movement of a medical instrument. The medical instrument may be coupled to a robotic arm that is connected to a controller. The medical instrument may have a plurality of functions such as wrist locking and motion scaling. One of the functions may be selected through a graphical user interface operated by the end user. The handle may have a plurality of buttons. One of the buttons may allow the end user to control the selected function. For example, when wrist locking/unlocking is selected, depressing the button can toggle the medical instrument wrist between a locked state and an unlocked state.