A patient-supporting device is disclosed. The patient-supporting device includes a fastening assembly that fastens the patient-supporting device to a structural member, a support member configured to receive a body part of a patient, and a height adjustment assembly that adjusts a distance between the fastening assembly and the support member. The height adjustment assembly includes a locking assembly and an elongated member. The support member is attached to a first end portion of the elongated member. The locking assembly is stationary relative to the fastening assembly. The elongated member is guided in an aperture of the locking assembly in a longitudinal direction of the elongated member. A plurality of first snap-in recesses is disposed on a first side portion of the elongated member. The locking assembly includes a first locking member.