A post assembly with illuminated information includes a hollow tube extending upwardly from a ground surface, the tube having a sidewall with textual or graphical information cut therethrough. The base or strut is maintained in position on the lower leg while the sole may be rotated, slid, or completely removed for allowing inspection and access to the plantar surface of the patient’s foot. The plug is configured for co-operating with an adjustment element belonging to the dosage system when the plug itself is at least partially inserted in the charging passage, particularly in such a way that a movement of rotation manually imparted on the plug will bring about a movement of rotation of the adjustment element.