Many practitioners confuse the terms impairment and disability. Disability refers to an individual's inability to complete a task or a duty. Disability is an alteration of the individual's capacity to meet personal, social, or occupational demands or statutory or regulatory requirements because of an impairment. Disability arises from a discrepancy between the limitations an impairment places on an individual and the external tasks that must be performed (eg, tasks in an occupational setting).
Impairment, however, is an artificial construct—usually one the legal system creates—to attempt to quantify the person's diminution in health. According to the fourth edition of the AMA Guides, "An impairment is a deviation from normal in a body part or organ system and its functioning." However, normal is a vague term that varies greatly depending on many factors, such as age and sex. Normal is not a fine point or an absolute reference in terms of physical and mental functioning or good health. Most often, normality is a range or a zone, as it is with vision and hearing.
Many state disability systems adopt an impairment guide or schedule for calculating damages. For example, Florida has adopted the Florida Uniform Permanent Impairment Rating Schedule (FUPIRS). This schedule is loosely modeled after the AMA Guides and purports to give impairment ratings based on various injuries or illnesses.
As a practical example, an individual may have minor impairment and still be considered totally disabled. For instance, an uneducated bricklayer may have 5% impairment due to lumbar strain. His physical restrictions may make it impossible for him to continue working in his field, and if he does not have the education to be retrained, he is effectively unable to return to work. Therefore, the extent of his impairment may be only 5%, but he is l00% disabled in terms of employment. In another example, a noted author and lecturer may have sustained a catastrophic injury causing thoracolumbar paraplegia. His impairment rating may be 70% according to the AMA Guides. However, because he can continue his work with little to no interruption, he may be considered to have no vocational disability.
In summary, the impairment rating alone, without a consideration of the extent of disability and loss of function, does not provide a complete picture of the effect of illness or injury on a particular individual.
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