Shock wave therapy is a newer method of treatment for tennis elbow. Pulses of high-pressure (low energy) sound are directed at the injured part of the tendon.
The "shock" refers to the high pressure. This pressure breaks down scar tissue. It helps new blood vessels grow in healthy tissue which can reduce pain. The treatment takes about 20 minutes once a week. Three or four sessions are advised.
Studies of this treatment have mixed results. Some say it relieves pain while others say it doesn't work any better than anything else. It's not clear who the ideal patient is for this treatment. There are very few side effects so some people want to try it before going to something more invasive like surgery. A few patients report increased aching, soreness, or pain after treatment.