An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Koelbaek Johansen M, Graven-Nielsen T, Schou Olesen A, Arendt-Nielsen L.Koelbaek Johansen M, et al.Pain. 1999 Nov;83(2):229-34. doi: 10.1016/s0304-3959(99)00106-2.Pain. 1999.PMID: 10534594