How is knee extensors (quadriceps) MMT performed?

• A. Seated or short-lying with the knee extended against resistance applied at the anterior lower leg; stabilize the thigh
• B. Prone with knee flexed and resistance on the posterior thigh
• C. Standing with the knee flexed
• D. Supine with leg lifted and no resistance

Answer: (A)

Testing the knee extensors focuses on the quadriceps producing knee extension against resistance while the limb is stabilized to prevent compensations. Have the patient seated (or in a short-lying position) so the knee can move through extension from a flexed start. The tester applies resistance to the anterior aspect of the lower leg, just above the ankle, as the patient attempts to straighten the knee. Stabilizing the thigh keeps the movement isolated to the knee and prevents the hip or trunk from helping, ensuring the test truly measures quadriceps strength.

This setup isolates knee extension, rather than testing hamstrings or other motions. Other positions described would either test different muscles or fail to provide the necessary resistance to elicit a meaningful measure of knee extension.