The purpose of the test is to distinguish between leg paresis that is psychogenic from that which is genuine. Genuine leg weakness seen in paresis is considered to be "organic," and other causes of leg paresis that is not related to a neuropathological process is considered to be "nonorganic."
Hoover's sign is a motor sign. It is based on the principle of crossed extensor reflex. The patient is placed in a supine/recumbent position. The examiner places his/her hand under the patient's heel. The patient is then instructed to press the heels down onto the table. The examiner is expected to feel pressure on the non-paretic limb. The patient is then asked to raise his/her non-paretic limb against downward resistance applied by the therapist. No pressure is expected to be felt under the paretic leg that is on the table. The Hoover's sign is when pressure is felt the paretic leg when the non-paretic leg is raised and no pressure is felt in the non-paretic leg when the paretic leg is being raised.
Provide the evidence for this technique here.
- Ziv, I., Djaldetti, R., Zoldan, J., Avraham, M., Melamed, E. (1998). Diagnosis of "non-organic" limb paresis by a novel objective motor assessment: The quantitative Hoover's test. Journal of Neurology, 245: 797-802.
- Kaufman, D.M. (2007). Clinical neurology for psychiatrists: 6th edition. Elsevier Health Sciences. p. 20.
- online video, http://www.youtube.com/watch?v=F4Fk_ZzCX6A, last accessed 6/2/2009
- Clinically Relevant Technologies, http://www.youtube.com/watch?v=QqQuPL36loM, last accessed May 2011
Koehler, P.J., Okun, M.S. (2004). Important observations prior to the description of the Hoover sign. Historical Neurology. 63: 1693-1697.
Larner, A.J. (2001). A Dictionary of Neurological signs. Springer.