Passing alternating radiofrequecy energy through tissues without significantly heating it can selectively inactivate pain-carrying nerve fibres, which tend to be smaller in diameter than the fibres that control muscles and allow normal sensation. Conventional radiofrequency treatment results in the coagulation of all tissues at the tip of the needle, including all nerve tissue. In most situations this does not matter, but in some situations it is important to maintain as much normal nerve function as possible.