Jul 03, 2007 · This Site Might Help You. RE: What is the difference between tonic and phasic receptors? Give one reason why the Jendrassik maneuver may produce a response with greater amplitude than the involuntary knee-jerk. AAN members must change their passwords on the AAN site. For assistance, please contact: AAN Members (800) 879-1960 or (612) 928-6000 (International) Non-AAN Member subscribers (800) 638-3030 or (301) 223-2300 option 3, select 1 (international) Jendrassik maneuver: The Jendrassik maneuver is a medical maneuver wherein the patient flexes both sets of fingers into a hook-like form and interlocks those sets of fingers together (note the hands of the patient in the chair). This maneuver is used often when testing the patellar reflex, as it forces the patient to concentrate on the ... May 24, 2011 · Explanation of the use and mechanisms of the Jendrassik maneuver. AFAIK it's a 'cheat' - it doesn't really do anything except distract the patient's attention so that they relax their leg. (The knee jerk doesn't work unless the patient's leg is relaxed in order to relax the tendon, so if they're not relaxing it you ask them to do the Jendrassik, which means they concentrate on their hands and relax their leg).