A safety device for a robotic arm, such as for a surgical robot, comprises first and second operation switches (deadman switches) 114,116 located on a handle 118 and operable by the same hand of an operator, both of the switches must be activated by depression against a biased on position to enable operation of the robotic arm. Upon depression of both switches, electromagnetically braked joints 102-112 are released from a locked position, permitting an operator to manoeuver the robotic arm 100. Also disclosed are lockout means preventing movement of a surgical tool when its movement outside of a defined workspace is detected, and the locking of electromagnetically braked joints of a robotic arm when a position sensor associated with an electromagnetically braked joint is detected approaching a spatial threshold.
