person who uses a wheelchair. Embedded in this is the notion of some disabling event, a period of adjustment and rehabilitation, and then the resumption of as full a life as possible with the assistance of any necessary assistive devices or accommodations. With many impairments, the reality of disability is somewhat different. The majority of individuals in the working-age population with long-term activity restrictions report that this restriction is due to musculoskeletal, circulatory, or respiratory disorders (LaPlante and Carlson, 1996). These conditions may also be associated with varying degrees of “illness,” so that it is not just an issue of physical performance. There are also considerations of pain, fatigue, and other symptoms. Many of these conditions are episodic in nature and may have trajectories of either deterioration or recovery (the latter being less common). This means that, apart from any environmental barriers or facilitators, the day-to-day or month-to-month experience of disability may be variable. This may need to be taken into account in any measurement scheme.
All disablement concepts appear to have been addressed, at least to some extent, as part of efforts to assess work disability.
Under some circumstances knowledge of the health condition or pathology contributes to an assessment of work disability. Medical listings of diagnosis and medical severity have been used by some agencies to identify individuals who would be unlikely to benefit from vocational rehabilitation (Reno, 1999). Such listings have also been applied in the context of Social Security disability determinations. Concern has been expressed because the use of such listings might, on the one hand, deny benefits to individuals who need them and might, on the other, award benefits to those who could still work. Such concerns are a reflection of the many steps in the disablement model between the health condition and work disability.
Assessments of work disability, or at least of entitlement to compensation for work injury, are often made at the level of impairment. The classic assessment is perhaps what has been pejoratively referred to as the “meat chart” assessment of the consequences of traumatic injury. An example of this would be the American Medical Association Guides to the