What are the three basic elements of rating for a knee disability?

• A. Limitation of flexion and extension, instability, calf atrophy
• B. Limitation of flexion and extension, instability, thigh atrophy
• C. Adduction, abduction and calf atrophy
• D. Adduction, abduction and thigh atrophy

Answer: (B)

The essential idea is that knee disability rating looks at how the knee’s function is actually limited and supported. The three elements to gauge are:

• Limitation of flexion and extension: how much the knee cannot bend (flexion) or straighten (extension). This directly affects daily activities like walking, climbing stairs, and standing, so it’s a primary measure of impairment.

• Instability: whether the knee remains stable or gives way due to ligament injuries. Instability reflects structural support failures and has a major impact on safety and mobility.

• Thigh atrophy: wasting of the thigh muscles, which often accompanies knee problems and reduces the strength and control around the knee joint.

Other options mix movements or muscle groups that aren’t the standard focus for knee rating (for example, adduction/abduction are not core knee movements, and calf atrophy is less directly tied to knee function).