ICIDH. It uses these terms to describe the inter-relationship, aiming to achieve consistency in the meaning and use of the labels. The focus is on functional difficulties.
A disease, disorder or injury creates an impairment causing an amendment in ordinary functioning. Impairment is the failure at the level of organs or systems of the body. This is the loss or abnormality of psychological, physiological or anatomical structure or function. A disability refers to the resulting fall or loss of capability to perform an activity in the manner considered normal for a human being e.g. climbing stairs or maneuvering a keyboard. A handicap is a social disadvantage resulting from an impairment or disability, which limits or prevents the completion of a normal role. (Mercer, 2003)
This medical model makes obvious the interplay of factors acknowledging that grey areas requiring understanding are acceptable within the definition. For purposes of evaluation, quite often what matters is not the medical condition but the complementary decrease or loss of function resulting from a disability. The social model separates an individual's exact impairment from his or her disability. In this loom, a person with impairment becomes 'disabled' when the organization of the society in which they live eliminates them from mainstream activities. The Royal College of Physicians stresses the need to think disability in the context of a disabled person's encounter with daily living, the environment and society, not only in exact circumstances, but also in the whole of that understanding. Then this can meet the needs of individual differences and concentrate on the external, reversible factors. Clarifying 'barrier-free' policies for everyone rather than 'special case' policies for people with labels creates a more dynamic loom (Mercer, 2003).
Another model incorporates the legal feature and includes the rights of the individual. In 1995, the current UK Disability Discrimination Act (DDA) was introduced to progress person beyond the limitations of the 1944 register for disabled people and the allocation system. The Act states that a person has a disability for the purposes of this Act if he has: 'a physical or mental impairment which has a substantial and long term adverse effect on his ability to carry out normal day to day activities.' The purpose of this legislation is to protect individuals with a disability, which makes it complicated for them to carry out ordinary, routine, day-to-day activities. The disability can cover physical, sensory, or mental faculties. It must be considerable and last for at least one year. The Act requires employers with fifteen employees or more to make 'reasonable provision' for disabled workers.
The financial stakes are high in case of disabled persons which results in inquiries around conclusion of legal, industrial, discriminatory, or insurance claims, assessment for medical aid, supply of high-tech equipment, provision of expensive prostheses, and access to special facilities, including education. Allocation of these increasingly expensive, sophisticated and necessarily limited resources always centers on the evaluation of the degree of disability. It is crucial to relate the disability to the level of persistent functioning. For