ICIDH-1980, ICF is intended for use by the broadest of audiences in the array of cultures, professions, and people affected by disabilities.

As noted above, the U.S. Secretary for Health and Human Services, along with other Ministers of Health, endorsed the ICF as an official member of the WHO family of classifications at the World Health Assembly in May 2001.

Conceptual Model

In response to feedback, the ICF has been written in neutral rather than negative terminology. Advocates and people with disabilities in particular pointed out that the negative perspective of ICIDH-1980 and its terminology often were perceived as a negative description of the person with the disability rather than as a descriptive term about the disabling situation itself. Thus, ICF has employed neutral terms to the extent possible.14 As with the ICIDH-2, the ICF envisions three components: body functions and structure, activities, and participation. Body functions are the physiological functions of body systems including psychological functions. Body structures are anatomical parts of the body such as organs, limbs, and their components. An activity is the execution of a task or action by an individual. Participation is involvement in a life situation. Decrements or disabilities in these three domains are respectively considered impairments, activity limitations, and participation restrictions. Impairments are problems in body function or structure as a significant deviation or loss. Activity limitations are difficulties that an individual may have in executing activities. Participation restrictions are problems an individual may experience in involvement in life situations.

Contextual factors are a significant addition to the conceptual formulation of ICF. Contextual factors include both personal and environmental factors. Environmental factors are the physical, social, and attitudinal backgrounds of the person. They are external to the individual and may have a positive or negative impact on the person’s functioning. Inclusion of the list of environmental factors is an innovation of the ICF. Personal factors, such as gender, age, and level of education, also have an important impact on the person’s functioning but are not listed in the ICF.

The conceptual model of ICF is an interactive one. ICIDH-1980 was linear. Not only does the health condition have an effect on the function and structure of the body, on the limitation of a person’s performance of


For example, “work” is a neutral term. ICF retains that neutrality by classifying it under the component of “activity” (also a neutral term) but uses a negative rating of difficulty to assess limitations in the performance of activities.

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