People with both visual and mobility impairments have great difficulty using conventional mobility aids for the blind. As a consequence they have little opportunity to take exercise without assistance from a carer. The combination of visual and mobility impairments occurs most often among the elderly. In this paper we examine the issues related to mobility for the blind and pay particular attention to the needs of the elderly or frail. We overview current mobility aids and detail some of the research in this area. We then describe a robot mobility aid "PAM-AID" that aims to provide both physical support during walking and obstacle avoidance. We examine the factors relevant to the operation of PAM-AID and give an overview of its design. Finally we describe the current status of the project and indicate its future direction.