The invention relates to a plaster-based (10) for a medical transfer seat (100) having a transverse direction (T), a seat (102), a frame (104) supporting the seat and adjustment means secured to the frame extending transversely under the seat.Characteristically, the plaster-based features: - mounting means (12) comprising a first end to be mounted on a portion of the seat adjusting means, and a second end (18)； - support means (14) mounted on the second end and configured to support a portion of a lower limb of a user disposed on the seat； - the first end of the mounting means being configured to slide along the adjusting means in the transverse direction, so that the plaster-based alternately takes a left and a right position position.
