THE KNEE-JERK IN PARESIS

A study of the knee jerk.

un 2 00 6 The knee - jerk mapping

We claim to give the definitive theory of what we call the ‘kneejerk mapping’, which is the basis for a class of optimization algorithms introduced by Baum, and promoted by Dempster, Laird, and Rubin under the name ‘EM algorithm’. Introduction We give the definitive theory of the knee-jerk mapping, to be defined below. This mapping has been investigated by many people, most notably Baum ([2], [...

Eliciting knee jerk--a new method of reinforcement.

This study was designed to detect the sensitivity of different methods of eliciting knee jerks and to compare the conventional methods with the newly purposed maneuver. Knee jerk (a deep tendon reflex) was elicited in 123 apparently normal population (77 males and 46 females) with three different methods (1) without applying reinforcement, (2) applying Jendrassik maneuver (strong voluntary cont...

Knee joint angular velocities and accelerations during the patellar tendon jerk.

Tendon jerk (TJ) is one of the most commonly used clinical tests in differential diagnosis of human motor disorders. There remains some ambiguity in the physiological interpretation of the test, especially with respect to its association to the functional status of patients. The TJ test inputs a non-physiological stimuli, but it is unclear to what degree the kinematics generated during the TJ t...

Inverted knee jerk: a neglected localising sign in spinal cord disease.

Two cases are described in which inversion of the quadriceps jerk was observed. It is suggested that the finding of an inverted quadriceps jerk is evidence of a spinal cord lesion at 12, 3, 4 segmental level and has for the lumbar cord the same localising value as the inverted supinator jerk for the cervical cord.