The role of inflow and outflow signals in judgments of limb position has been debated for over a century. A previous study suggested that illusions of movement do not accompany the motor commands used in attempts to move a paralysed limb (McCloskey & Torda, 1975; for review see Gandevia, 1987). We used ischaemic paralysis of the arm to generate a phantom hand and found that its perceived position changed with attempted contractions. Six naïve human subjects were used. Subjects had their right hand held, fingers extended, in a frame which could rotate about the wrist. Subjects used their left hand to signal with a pointer the perceived position of the right wrist. The wrist was passively moved to different positions and the subject matched its position with muscles relaxed, and during sustained isometric efforts of 30% maximum in flexion or extension. Matches were repeated when the arm and hand was paralysed by ischaemia using a cuff on the upper arm. All voluntary movements and all sensations, apart from pain with a skin pinch, were abolished from just below the elbow. Before paralysis, subjects accurately detected wrist position when the hand had been passively moved. Performance was similar when position was matched while subjects exerted moderate flexion or extension efforts at a given angle. The mean change from the passively matched position was small, 2.4±4.4 deg (mean±SD) in the direction of flexion with flexion contractions and 5.4±7.0 deg in the direction of extension with extension contractions (flexion vs extension, paired t test, P=0.06). During paralysis, all subjects experienced a phantom hand with the extended fingers perceived as flexed. Then, when attempting to flex or extend at any wrist position subjects showed large illusions of displacement, in the direction of flexion for flexion efforts (by 21.1±12.7 deg) and in extension for extension efforts (30.5±12.6 deg, P=0.002). This result establishes a definitive a role for outflow signals in position sense and sheds new light on the sensory processes underlying the generation of phantom limbs.