Hoover's sign

Hoover’s sign is a maneuver aimed to separate organic from non-organic paresis of the leg. The sign relies on the principle of synergistic contraction. Involuntary extension of the "paralized" leg occurs when flexing the contralateral leg against resistance. It has been neglected, although it is a useful clinical test. Essentially, you hold your hand under the contralateral heel and ask the patient to extend the leg off the bed. If you feel pressure from the contralateral heel, the weakness is likely organic. If no pressure is felt, the patient is likely suffering from non-organic limb weakness.

Charles Franklin Hoover (1865–1927) was an American physician born in Cleveland, Ohio, who read medicine at Harvard. He worked in Vienna under Neusser, and in Strasburg with F Kraus before returning to Cleveland. He was appointed Professor of Medicine in 1907. His main interests were in diseases of the diaphragm, lungs, and liver.

Another Hoover’s sign is inward movement of the lower rib cage during inspiration, implying a flat, but functioning, diaphragm, often associated with COPD