Abstract: Seating device (1) comprising a base plate (2) for a user to sit on and a pelvic support (3) for supporting in a vertical position the pelvis of a user sitting on said base plate (2) without supporting or immobilising said user's vertebrae, wherein said pelvic support (3) is configured for contacting said pelvis (9) at the posterior superior iliac spines (PSIS) (91) and/or at the iliac crests (92), without any contact to said user's vertebrae wherein said seating device is configured for maintaining an angle of 93° to 97° between the vertically supported pelvis (9) and the femoral bones of said user. In embodiments, the seating device includes a mechanism to encourage the user's upper body mobility, for example a convex base.