What Is Hoover's Sign?

In medicine, two Hoover’s signs exist, both named for Ohio physician Charles Franklin Hoover. One Hoover’s sign refers to a pulmonary test, and the second tests for true incomplete paralysis in one leg. The test for the sign comes in two parts and is performed while the patient lies on his back on an examining table and the doctor, standing at the patient’s feet, places her hands under the patient’s heels. During the exam, the patient is asked to raise and lower the partially paralyzed leg and the sound leg while the downward pressure of the stationary leg is evaluated.

A neurologist is frequently called upon to assess unilateral paralysis or paralysis on one side of the body. One of the conclusions a neurologist must make during a physical exam is whether the unilateral paralysis is a real, partial paralysis caused by disease and tissue damage or whether the paralysis is hysterical or emotionally driven. Hoover’s sign is a tool that can be used to identify true and hysterical unilateral paresis in the lower limbs.

In preparation for the test for Hoover's sign, the patient is asked to lie down on an examining table on his back with his legs out straight. The heels of the feet should be resting on the table with the feet at a right angle to the table. Before this sign is tested, the doctor typically performs a strength test to evaluate the strength of the patient’s hips. This is done by asking the patient to raise and lower each leg while the examiner uses her hand to provide a slight opposing resistance against the leg.

There are two parts to the test for Hoover’s sign. For both parts of the test, the examiner stands at the end of the table, facing the patient’s feet, and places one hand under each heel. In part one of the test, the patient is asked to raise his sound leg while the doctor evaluates the downward pressure of the partially paralyzed leg into the palm of her hand. If the descending pressure in the doctor's hand is equivalent to the strength exhibited during the strength test, then the paralysis is thought to be hysterical. When the downward force into the hand of the doctor is weaker than the strength test, then the partial paralysis is considered to be real or the result of a neuromuscular problem.

In the second part of the test for Hoover's sign, the partial paralyzed leg is lifted and the descending pressure of the sound leg into the doctor’s hand is evaluated. If the downward pressure of the sound leg is minor and the doctor is simultaneously able to easily lift the sound leg, then the partial paralysis is considered to be hysterical. When the downward force of the sound leg is strong, then the partial paralysis is considered real.