A systematic review including 22 studies with a total of 1 953 subjects was abstracted in DARE. 16 studies compared ultrasound to sham ultrasound. Pooled standardised effect size d/s (obtained by dividing the difference between the ultrasound effect and the control group effect by the range of the outcome measurement used) was 0.64% (95% CI –6.7% to 7.5%).
Another systematic review including 38 RCTs or CTs was abstracted in DARE. 13 studies scored five or more on validity criteria of the Amsterdam-Maastricht Consensus List. With the possible exception of lateral epicondylitis (3 studies producing a difference in success rates of 15%, NNT = 7), there was little evidence of the effectiveness of ultrasound therapy in various musculoskeletal conditions.
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in interventions and outcomes).