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

What are the three basic elements of rating for 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 key idea is that knee disability rating is based on three observable impairment areas: how much the knee’s motion is limited (flexion and extension), how stable the joint remains under stress (instability), and the degree of muscle wasting in the thigh (thigh atrophy) reflecting loss of supporting muscle around the knee. Limitation of flexion and extension measures the range of motion and functional capability; instability assesses ligamentous support and the tendency of the knee to give way; thigh atrophy indicates muscle decline that directly affects knee stability and function. Among the options, the one that lists these three elements—limitation of flexion and extension, instability, and thigh atrophy—matches the standard components used to rate knee disability. Calf atrophy is less directly linked to knee joint impairment, and adduction/abduction are movements not used as the core rating elements for knee disability.

The key idea is that knee disability rating is based on three observable impairment areas: how much the knee’s motion is limited (flexion and extension), how stable the joint remains under stress (instability), and the degree of muscle wasting in the thigh (thigh atrophy) reflecting loss of supporting muscle around the knee. Limitation of flexion and extension measures the range of motion and functional capability; instability assesses ligamentous support and the tendency of the knee to give way; thigh atrophy indicates muscle decline that directly affects knee stability and function. Among the options, the one that lists these three elements—limitation of flexion and extension, instability, and thigh atrophy—matches the standard components used to rate knee disability. Calf atrophy is less directly linked to knee joint impairment, and adduction/abduction are movements not used as the core rating elements for knee disability.