The purpose of the research is to study the effects of two different injection therapies for the treatment of lateral epicondylitis (tennis elbow). Specifically, we will look at which therapy provides better short and long-term relief of pain, which treatment allows better function and less disability, and which treatment gives back better strength in the affected hand. Each subject will receive only one of the two treatments. Although both of these treatments are usually very well tolerated, it is important to make this comparison because it is believed that one of these therapies may have better long term effectiveness, with a lower cost, and smaller number of potential side effects.