Patient's question:
NoDoctor's answer:
Inserting a finger can simply test the tightness of YD. However, the prerequisite is: YD should be sufficiently moistened (i.e., commonly referred to as "flowing water"), because during ML, YD is wet; secondly, YD must be relaxed, because during ML, YD is in a receptive state and will not contract—typically, when inserting a finger, YD instinctively tightens.