Testing _________ extremity, support the patient's thigh with one hand, grasp the foot with the other and flex and extend the patient's knee and ankle on each side

• A. Lower
• B. Upper
• C. Both
• D. Spine

Answer: (D)

This approach tests the spinal motor pathways that control the legs. By supporting the thigh with one hand to stabilize the proximal segment and grasping the foot with the other to move the knee and ankle through flexion and extension on each side, you’re evaluating how well the lower limbs respond to voluntary movement that originates from the spinal cord. Checking both sides lets you compare for symmetry, which helps distinguish spinal involvement from a localized joint issue. In the lower limbs, knee extension and flexion involve the lumbosacral segments (e.g., quadriceps and hamstrings with related nerve roots), and ankle movements reflect further downstream spinal control. This bilateral lower-limb motor testing essentially probes the effectiveness of the spinal pathways that innervate the legs, which is why the spine is the focus here.