Patient recruitment would skyrocket when the study involves bodily exposure if examinations were made by staff who are the same gender as the patient.  This is critical when patients are seeing strangers for their privacy and dignity.  Try it, it works!

It is a mistake to ignore the emotion humiliation. It is motivation for the greatest avoidance.   When putting patients in a position where they have to be exposed in front of members of the opposite sex you will not receive cooperation.  It's that simple.