Abstract: A kinematical chain (100) for assisting a spherical motion of an anatomical joint (200) of a finger of the hand (210) of a user, said anatomical joint (200) having centre of rotation P and being arranged for allowing a relative motion of a finger of the hand (210) with respect to a portion of hand (220) of the user, said finger of the hand (210) defining a longitudinal direction ?. The kinematical chain (100) comprises a first rotational joint (110) engaged to the finger of the hand (210) and to a first connection link (115), said first rotational joint (110) arranged to provide a relative rotation ? between the first connection link (115) and the finger of the hand (210) about a rotation axis x coincident with the longitudinal direction ?.

Abstract: A rotational joint of intra-extra rotation (100) for assistance of the movement of intra-extra rotation of a shoulder of a user, said rotational joint (100) comprising a first circular guide (110) arranged to rotate about a rotation axis r, a second circular guide (120) arranged to rotate about a rotation axis r? parallel to the rotation axis r, an support element (130) arranged to support the first and the second circular guide (110, 120). The first and the second circular guide (110, 120) are pivotally connected by a conical wheel (140) having rotation axis s perpendicular to rotation axes r and said conical wheel (140) being pivotally constrained to the support element (130). When the conical wheel (140) makes a rotation ? about its rotation axis s, the first circular guide (110) makes a rotation ? about its rotation axis r and, at the same time, the second circular guide (120) makes a rotation ??=?? about its rotation axis r?.