Which best defines functional limitation in the Nagi model?

• A. Loss or abnormality at the tissue/organ level.
• B. Inability to perform an action in a normal way due to impairment.
• C. Restriction in performing a socially defined role.
• D. Environmental factors define limitation.

Answer: (B)

Functional limitation refers to the reduced ability to perform basic actions or activities because of an underlying impairment. It describes how an impairment translates into trouble with everyday tasks, such as walking, climbing stairs, or reaching overhead, when done in a normal manner. In the Nagi model, impairment is the actual tissue or organ abnormality, functional limitation is the consequence at the person level in performing actions, and disability represents broader limitations in fulfilling social or role expectations. Environmental factors can influence disability but don’t define functional limitation itself.