A mobility system for providing mobility assistance to a user, the system comprising a wheeled base, an exoskeleton assembly, and a docking assembly arranged to selectively support the exoskeleton assembly on the wheeled base, the wheeled base comprising a base frame and wheels supporting the base frame for rolling movement along the ground and the exoskeleton assembly comprising: an upper portion arranged to be braced to a torso of a user; an intermediate portion comprising two upper leg members independently pivotally connected to the upper portion and arranged to be braced to respective thighs of the user; a hip joint pivotally coupling the intermediate portion to the upper portion; a lower portion comprising two independent lower leg members arranged to be braced to respective lower legs of user; and a knee joint comprising two pivot connections pivotally coupling the lower leg members of the lower leg portion to the upper leg members of the intermediate portion respectively; the docking assembly being operable between a coupled position in which the exoskeleton assembly is coupled to the wheeled base and the exoskeleton assembly is movable relative to the wheeled base between respective standing and sitting positions and a released position in which the exoskeleton assembly is readily separable from the wheeled base in the standing position of the exoskeleton assembly the mobility system being characterized in that: the exoskeleton assembly further comprises position control motor units associated with the hip and knee joints; the exoskeleton assembly is configured to provide a walking motion to the user in the standing position of the exoskeleton assembly; the exoskeleton assembly is movable relative to the wheeled base between the standing position and the sitting position in the coupled position of the docking assembly solely under control of the position control motor units; and the position control motor units are separable from the wheeled base together with the exoskeleton assembly. an upper portion arranged to be braced to a torso of a user; an intermediate portion comprising two upper leg members independently pivotally connected to the upper portion and arranged to be braced to respective thighs of the user; a hip joint pivotally coupling the intermediate portion to the upper portion; a lower portion comprising two independent lower leg members arranged to be braced to respective lower legs of user; and a knee joint comprising two pivot connections pivotally coupling the lower leg members of the lower leg portion to the upper leg members of the intermediate portion respectively; the docking assembly being operable between a coupled position in which the exoskeleton assembly is coupled to the wheeled base and the exoskeleton assembly is movable relative to the wheeled base between respective standing and sitting positions and a released position in which the exoskeleton assembly is readily separable from the wheeled base in the standing position of the exoskeleton assembly the mobility system being characterized in that: the exoskeleton assembly further comprises position control motor units associated with the hip and knee joints; the exoskeleton assembly is configured to provide a walking motion to the user in the standing position of the exoskeleton assembly; the exoskeleton assembly is movable relative to the wheeled base between the standing position and the sitting position in the coupled position of the docking assembly solely under control of the position control motor units; and the position control motor units are separable from the wheeled base together with the exoskeleton assembly. the exoskeleton assembly further comprises position control motor units associated with the hip and knee joints; the exoskeleton assembly is configured to provide a walking motion to the user in the standing position of the exoskeleton assembly; the exoskeleton assembly is movable relative to the wheeled base between the standing position and the sitting position in the coupled position of the docking assembly solely under control of the position control motor units; and the position control motor units are separable from the wheeled base together with the exoskeleton assembly.