Digital human modelling (DHM) tools have been introduced in industry, mainly in automotive, aerospace and industrial engineering, to facilitate a proactive and efficient consideration of ergonomics in the design process. The employment of DHM tools in the health care sector calls for customisation work to be carried out in order to make the tools fit the design activities. The human model, i.e. the computer manikin, needs to be modified since it has the characteristics and appearance of an able healthy young or middle-aged human, but the resident or patient is frequently an elderly person with impairments of some kind. This paper suggests concepts and structures for assigning the computer manikins characteristics of the elderly. These changes are made by the modification of anthropometric and joint range of motion data in the DHM tool, and by assigning narrative descriptions to the manikins and more age-corresponding appearances. The objective is to define a manageable number of representative manikins that will support a proactive and user-centred design process in the health care industry, and in other types of design processes for the elderly, or in an inclusive design context.