An Updated Systematic Review of Turnout Position Assessment Protocols Used in Dance Medicine and Science Research

Abstract
Turnout, or external rotation of the lower limbs, is an integral part of classical ballet technique. Contributions of lower limb structures to turnout can be separated into HER (hip external rotation) and NHCTO (non-hip contributions to turnout). This study aimed to review systematically methods used to measure turnout in dance medicine and science research, thereby updating the literature since the Champion and Chatfield review of 2008. CINAHL, EMBASE, PubMed, and Web of Science were searched in January 2018 by two independent reviewers. Peer-reviewed studies measuring turnout in dance were included, except those published prior to March 23, 2006, as that was the last date of publication included in the previous review. Abstracts, theses, and editorials were excluded. From each study, study design, population (sample size, sex, age, genre of dance, and level of training), details of the protocol used, and result of turnout measurement were extracted, as well as reliability data. All included studies were assessed for risk of bias, using either Newcastle-Ottawa scale, AXIS tool, or PEDro scale as appropriate for each study design. A total of 41 studies met the inclusion criteria. Twenty-eight studies measured HER, nine measured NCHTO, and 22 measured total turnout (TTO). An increased number of studies investigated TTO (N = 22; N = 4 passive TTO) and NHCTO (N = 9) since 2006. All studies scored above half the points attainable from their respective tools. Results suggest HER remains the most common protocol for measuring turnout (N = 28), despite the fact it disregards input from structures below the hip. It is concluded that researchers should focus on quality of reporting of protocols to ensure repeatability and facilitate comparison of results. Future studies should include absolute reliability and validity testing of all currently used protocols so that standardization can be fully achieved.