A number of new therapies have been developed for treating chronic pain. Most borrow from the field of anesthesiology and share a goal of preventing pain signals from reaching the brain. Implantable devices or on-skin electrodes can stimulate nerves to mask pain. "Another technique, known as facet joint denervation involves inactivating nerves in the joints that enable the spine to bend and twist, such as in the neck, by passing radio waves via needles inserted through the skin to heat the tissue at the tip of a joint. Other devices and procedures deliver drugs directly to the site of pain, such as nerve blocks, which use injections to numb nerves including in a shoulder or arm."