The present invention relates to a joint
assembly (1) for a
robot (100), comprising a housing (26) connected with an output part (8), the housing comprising a housing wall (26A), a
strain wave gearing system (90) comprising a wave generator (7), a flexspline (13), and a circular spline (36) connected to the output part (8), wherein the wave generator (7) is rotated by a rotor shaft (3), the rotor shaft being driven by an
electric motor (140) comprising a
stator (15) and a rotor
magnet (16), the rotor
magnet (16) being affixed to the rotor shaft (3), and wherein the joint
assembly (1) further comprises a rotor
brake (30) configured to stop / prevent relative movement between the rotor shaft (3) and the flexspline (13), and sensors arranged to measure the position of the housing (26) in relation to the output part (8). Furthermore, the present invention also relates to a
robotic arm (100) comprising a joint
assembly according to the present invention and to the use of the joint assembly according to the present invention.