"Tennis elbow," characterized by pain and inflammation in the upper arm near the elbow and caused by repetitive movements in the wrists or forearms (such as the movements involved in playing tennis), may be relieved by injections of the drug botulinum toxin (botox). However, the pain relief comes with the possibility of some bothersome side effects.

At the Imam Khomeini Hospital Complex at Tehran University in Iran, researchers injected botox in the arms of patients with tennis elbow who had not found relief from previous treatments. The researchers customized the location of the injection site based on the length of each patient's forearm, as an inexact injection site can lead to insufficient paralysis.

Side effects caused by the injections included reduced strength levels, and the partial loss of ability to move the third and fourth fingers of the hand. Although pain levels were reduced in the patients, the lack of long-term research and the adverse effects of the injections make some cautious about their use. More research is warranted to determine if botox injections are a suitable treatment for tennis elbow.