Folding seat comprising a shoulder rest forming a standing aid

The seat has a casing (2) with a rotatable base (3) and a backrest that has a lower unit constituting a lumbar support and an upper unit (5) constituting a scapular support (5A) on its one face. The casing has mounting points for a rotation axle of the upper unit that is moved from a raised position where its scapular support face (FA) is visible to a folded back position where its protection face is visible.