In a patellar tendon relfex does having the subject close hi

In a patellar tendon relfex, does having the subject close his or her eyes affect the response to the mallet strike? Why?

Solution

No, having the subject close their eyes does not affect the response to the mallet strike. This is because the knee-jerk reaction being looked for deals with reflex action associated with the L2, L3 and L4 segments of the spinal cord, and not cranial nerves. The stimulus here is supposed to be the striking of the patellar ligament with a reflex hammer, not the visual information of the practitioner doing so.