Emptiness and physical pain
Pain is just pain, it is empty of a self, it isn't a self; does not belong to a self; is empty of an owner

Seen as being empty of the quality of self or belonging to a self; there does not come to be an 'I am' in regards to the pain; there being no 'I am' in regards to the pain there is no 'I am experiencing pain'; there being no 'i am experiencing pain' there is no 'i am bad because i am experiencing pain'; there being no 'i am bad because i am experiencing pain ' there is no 'may i not be experiencing pain'

Understanding emptiness in this sense removes the basis for aversion that could arise in regards to a painful feeling