Position of the elbow in determination of abnormal motor conduction of the ulnar nerve across the elbow.

Routine evaluation of patients for suspected ulnar neuropathy includes testing of motor conduction velocity across the elbow, although the best position of the elbow for this test is controversial. The preferred testing position--elbow flexion or extension--was studied by determining the yield of abnormality at both positions in patients selected for possible ulnar nerve abnormalities unrelated to motor conduction. We found no major differences between the flexed or extended position of the elbow except that normal values for each of these positions varied. The yield of abnormal findings was greatest from measuring absolute motor conduction velocity across the elbow as opposed to comparing the difference in velocities between the elbow and either adjacent segment.