In the Nagi model, impairment refers to?

• A. Loss or abnormality at the tissue/organ level.
• B. Occurs at the cellular level.
• C. Inability to perform activities.
• D. Social role restriction.

Answer: (A)

Impairment is the loss or abnormality at the level of body tissues or organs. It describes changes like reduced joint range of motion, muscle weakness, or a structural deformity that you can observe or measure in the body itself. This is different from the inability to perform activities (functional limitation) and from restrictions in social roles (disability). So, when arthritis limits a patient’s elbow motion, that’s an impairment—the disease has produced a tissue/organ-level change. The pathway would be pathology leading to impairment, which can then contribute to limitations in function and, ultimately, disability, but the impairment itself is defined at the tissue/organ level, not at the cellular level or at the level of activities or social roles.