• Epidemiology
• ergonomics

Research to assess ergonomic interventions that aim to improve the musculoskeletal health of workers is, for good reason, criticised as being of poor quality. Study design can be inadequate with poor or missing control groups, risk of bias and confounders potentially influencing the outcome. Many ergonomic intervention reviews have made this point, from the early review of Westgaard and Winkel1 to the review by Driessen et al2 published in this issue of OEM (see page 277). Researchers have responded to this criticism by upgrading study design, and in some studies aiming for the gold standard of randomised controlled trials (RCTs). Secondary to this development, recent reviews of ergonomic intervention have performed an extensive pruning of studies on the basis of flawed design (eg, Brewer et al3, Burton et al4, Boocock et al5), culminating in the review by Driessen et al2 who only included RCT studies. Inclusion and exclusion criteria follow the Cochrane mould (Higgins and Green6). Literature searches for reviews have typically identified several thousands of potentially relevant studies, but with only …