A robotic exoskeleton apparatus (10) is adapted to provide assistive support for movement of a users shoulder and glenohumeral (GH) joint. The apparatus includes a base (12) adapted to be supported adjacent a shoulder (14) or upper arm of the user. A first link (16) is connected to the base by a first revolute joint (18) defining a first degree of freedom. A second link (20) is connected to the first link by a second revolute joint (22) defining a second degree of freedom. A third link (24) is connected to the second link by a third revolute joint (26) defining a third degree of freedom. A fourth link (28) is connected to the third link by a fourth revolute joint (30) defining a fourth degree of freedom. The links are connected in series and configured such that the respective axes of rotation substantially coincide at an intersection point (X) to form a virtual spherical joint with an instantaneous centre of rotation at the intersection point. The apparatus is supported such that in use the instantaneous centre of rotation of the virtual spherical joint substantially coincides with the GH joint, with the links sufficiently spaced apart from the GH joint to avoid collision with the user. The revolute joints collectively provide a redundant degree of freedom with respect to the virtual spherical joint, to facilitate control of the apparatus. Figure 8Linvention concerne un appareil robotique dexosquelette (10) conçu pour fournir un support dassistance pour le mouvement de lépaule et de larticulation gléno-humérale (GH) dun utilisateur. Lappareil comprend une base (12) conçue pour être soutenue à côté dune épaule (14) ou du haut du bras de lutilisateur. Une première liaison (16) est reliée à la base via une première articulation rotative (18), ce qui définit un premier degré de liberté. Une deuxième liaison (20) est reliée à la première liaison via une deuxième articulation rotative (22), ce qui définit un deuxième degré de liberté. Une troisième liaison (24) est relié
