Navigating the Complexity of Disability vs. Impairment in Earning Capacity Analyses

September 11, 2023

The definition of disability can vary depending on the context and the field in which it is being considered. General definitions of disability, as they pertain to the medical field and legal field are both considered.

The World Health Organization (WHO) defines disability as an activity limitation that creates a difficulty in the performance, accomplishment, or completion of an activity in the manner or within the range considered normal for a human being. Disabilities can be congenital, acquired through illness or injury, or may develop over time due to various factors.

Disability also refers to a condition or injury that substantially limits one or more major life activities of an individual. This definition comes from the Americans with Disabilities Act (ADA) in the United States, and similar laws exist in other countries. The ADA aims to protect individuals with disabilities from discrimination in various aspects of life, including employment, public services, and access to public accommodations.

In personal injury or medical malpractice litigation, disability typically refers to the physical or mental impairment(s) resulting from an accident or incident that has caused harm to an individual’s health, well-being, and ability to function. In this context, the type and level of disability is a crucial factor in determining the extent of an impairment resulting in potential economic damages.

Impairment refers to any loss or abnormality in the structure or function of a body part or system. It can be physical, sensory, cognitive, or mental in nature. Impairments may be permanent, temporary, or progressive. Impairment can be conceptualized as a symptom of disability, but the two terms two should not be used interchangeably. In fact, distinguishing the difference between impairment and disability is imperative, as an individual can be impaired significantly but have little to no disability, while another individual can be disabled with minimal impairment.[1]

For example, an individual who underwent a below the knee amputation following an accident may continue working full-time as a computer engineer and may be independent in all activities of daily living when they wear prosthesis. In this case, the individual may be considered disabled, but have no impairment in terms of their ability to work resulting in little to no economic losses.

As another example, a surgeon who sustains a relatively minor nerve injury that severely limits her ability to perform surgery would be significantly impaired but may not be considered disabled.

How does a vocational expert reconcile the complexities inherent in the concept of disability?

In a personal injury case, the vocational expert is tasked with considering an individual’s level of functioning as it pertains to their ability to maintain gainful employment and earn wages. Importantly, the presence of a disability within the personal injury context is considered through the functional limitations and the impact of those limitations on an individual’s employability.

Disability is clearly a complex concept, and a vocational expert should not use shortcuts when analyzing an individual’s type and level of disability and the impact of that disability on their ability to work and earn wages. While medical and legal definitions of disability can be helpful, and an individual’s self-report of their disability can be informative, there are many other factors that can affect earnings and employment, and these factors should be thoroughly considered when developing opinions about an individual’s earning capacity.

[1] Holmes, E. B., & Lorenzo, C. (2013). Impairment rating and disability determination. Medscape. Updated: Jan, 24.