Finally, although tertiary prevention might be where most prevention of disability itself occurs, primary and secondary strategies are essential elements of disability prevention because they intervene in the disabling process to reduce the likelihood of progression of predisposing conditions toward disability. Thus the public health and medical aspects of disability prevention are important, but should not overshadow or undercut the essential understanding of the social context of disability, as described throughout this report. Given the existence of predisposing functional limitations, the predominant means of disability prevention and amelioration are often social and economic.