Level 2: Mid-level evidence
Extracorporeal shock wave therapy (ESWT) for treatment of lateral elbow pain (tennis elbow) seemed ineffective in a Cochrane review, but the evidence is conflicting (Cochrane Database Syst Rev. 2005;:CD003524). Nine randomized, placebo-controlled trials (involving 1,006 patients) and one comparison trial with steroid injections in 93 patients were systematically reviewed.
Five of the trials showed little or no improvement in pain, function, or grip strength with ESWT, while four trials showed some improvement. Of 13 pooled analyses, 11 found no significant benefits of ESWT over placebo. One pooled result favored ESWT, showing an increased likelihood of achieving at least 50% improvement in pain with resisted wrist extension after 12 weeks (based on pooling of two trials with 192 patients).
However, this finding was not supported by four trials that could not be pooled. Steroid injection was more effective than ESWT for at least 50% reduction in pain from baseline to three months (84% vs. 60%, P < 0.05, NNT 4). Minimal adverse effects of ESWT included transient pain, reddening of skin, and nausea.