A test used to differentiate true inability to raise a leg, due to pain as a ruptured disk presses on a nerve in the lumbar region, from the malingering patient who states they have back pain and states that they cannot raise their leg.
With the patient in supine posture (lying on their back), place your palms beneath their heels.
Ask the patient to raise one leg.
A truely disabled person will involuntarily counterpressure with the heel of the other leg in effort to raise it.
Absence of counterpressure is evidence of a malingering patient.
Hoppenfeld, Stanley and Zeide, Michael S. 1993. Orthopaedic dictionary. Retrieved September 1, 2009 from http://books.google.ca/books?id=KZvdy9LPDNgC&pg=PA162&lpg=PA162&dq=Hoffmann’s+pins+and+bone+setting&source=web&ots=qQSLvTxrDR&sig=R-cYaT4T9K36fq-codN8V0oH6ZY&hl=en&ei=hamXSYLfCpWksAPi9YB8&sa=X&oi=book_result&resnum=4&ct=result#v=onepage&q=&f=false