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

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

Answer: (B)

The three basic elements of rating for a knee disability center around the functional movements and structural integrity of the knee. Limitation of flexion and extension is critical because range of motion directly affects mobility and the ability to perform daily activities. Instability involves assessment of the knee's ability to bear weight and maintain proper alignment during movement, which is essential for effectively evaluating impairments that could lead to further injury or functional loss.

Thigh atrophy is relevant as it reflects muscle wasting often associated with disuse or injury. When the muscles supporting the knee are weakened or atrophied, it directly impacts the joint's stability and overall function. Thus, the focus on these three elements provides a comprehensive picture of the knee's functionality and the severity of the disability.

The other options include incorrect elements that do not conform to the primary criteria used in rating knee disabilities. Adduction and abduction are movements that are less relevant in this context compared to flexion and extension. Additionally, calf atrophy does not directly relate to the assessment of knee disability like thigh atrophy does, as the muscles around the thigh play a more significant role in knee stability and function.