Known more properly as lateral epicondylitis, tennis elbow is a pain on the outside of the elbow.
It's caused by overuse of the muscles and tendons of the forearm, usually where that overuse is stenuous - for example tennis. But there can be other activities, not just sports, that cause "tennis elbow":
Any repetitive activity where there is continuous loaded pronation of the forearm may cause tennis elbow (which is why knitting is on the list). Pronation is the movement of turning your hand palm upwards.
Tennis elbow is more likely to occur when that repetitive pronation occurs with your arm fully extended (for example, tennis backhand). Most people who get tennis elbow don't play tennis
The obvious symptom is pain on the outside of the elbow: the test to see if it's likely that that pain is actually tennis elbow is to turn a door handle: if it hurts, then, yep, the chances are it's tennis elbow.
The pain is caused by strains in the tendons that attach to the bony lump on the outside of your elbow (the lateral epicondyle). The tendon becomes inflamed and therefore starts rubbing inside the sheath that protects it. The more that you use the painful elbow, the more it rubs inside it's sheath and the more it will become inflamed.
Given that tennis elbow is all about tendon inflammation, it will eventually clear up by itself if you don't use it. This can take anything from a few weeks to a few months.
If you want to speed up the healing process then remedial massage therapy may be able to help. But applying a lot of deep friction to your lateral epicondylitis may just inflame things further, so there are a lot of other treatments that a good therapist will do: trigger point therapy and deep tissue massage above and below the affected joint can help speed up your recovery.
Your therapist will also use other manual manipulation to encourage blood flow, reduce stiffness and encourage the flow of blood and nutrients to your forearm and to the damaged tendon.
You'll also be given exercises to help strengthen your forearm, so that you can get back to your activity as soon as possible.
As ever, if you think I can help, give me a call.