Review Article Measurement of Turnout in Dance Research A Critical Review Lowry M. Champion, M.F.A., and Steven J. Chatfield, Ph.D. Abstract procedure for assessing total turnout; rotation. Turnout measurement procedures, adoption of conventions for reporting Dance aesthetics often demand results, and reporting formats vary in data in compatible forms; and the de- what is considered “perfect TO,” with- dance medicine and science research, velopment of normative data sets for out regard to anatomical capabilities making comparisons difficult. It different categories of dancers. and limitations. Perfect turnout re- is agreed that turnout results from quires 90° of external rotation of each summative contributions of the he term “turnout” (TO) is extremity, establishing a 180° angle hip, knee, lower-leg, and the foot- commonly used in dance to between the longitudinal axes of the 1,3,5,8,11,12 ankle complex. However, the most denote external rotation of feet. This is a phenomenon Tthe lower extremities; in particular, that is anatomically and biomechani- frequently reported measurement is 1,12,15 hip external rotation, and even this is ballet uses a foundation of five turned cally uncommon. Of the desired measured in incompatible ways. No out positions of the feet: first, second, 90° of perfect unilateral external 1,2 normative data exist for component third, fourth, and fifth positions. rotation, the research suggests that a and summative measures or for dif- However, the term has many associa- range of 60° to 70° is contributed by ferent categories of dancers, making tions, and an operational definition the hip, while the distal aspects of the screening, clinical assessment, and has yet to be established. Some re- lower extremity contribute approxi- 2,4,12,16-18 research problematic. Thus, there searchers define TO as external rota- mately 10° to 35°. Findings by 19 is a need to standardize component tion of the legs such that the longitu- Hamilton and colleagues and Khan 6 measurements, develop an inclusive dinal axes of the feet establish a 180° and associates support the concept of 1-10 measurement procedure for total angle. One study further defines distal contributions by reporting that turnout, and establish normative data three distinct subcategories: “techni- approximately 40% of TO originates for each measurement and for differ- cally correct,” “functional,” and “com- from below the knee. These findings 1 ent categories of dancers. This review pensated” TO. “Technically correct” emphasize the need for a total TO evaluates the 24 published articles TO is the position, as determined by measurement inclusive of all compo- that have reported original data for dance instructors, in which the hips nents. turnout assessment in dancers. Results are maximally rotated externally and The degree of total turnout (TTO) are summarized and displayed for each weight is centered through the knee accessible during functional move- article. In conclusion, recommenda- and ankle. “Functional” TO is the ment is different between individu- tions are made for: use of selected hip position assumed by the dancer, and als, and is affected by several factors, external range of motion and tibial “compensated” TO is determined by including soft tissue and skeletal 2,5-7,15 version measurements as the most the difference between “functional” anatomy. While soft tissue char- important components of turnout; a TO and bilateral passive hip external acteristics (including ligamentous laxity, muscle stretch, and muscle strength) influence TO, the scope of Lowry M. Champion, M.F.A., is at Stanford University, Palo Alto, California. this review is limited to skeletal influ- Steven J. Chatfield Ph.D. is in the School of Music and Dance, University of ences. Skeletal features influential in Oregon, Eugene, Oregon. TTO include the following: orienta- Correspondence: Lowry M. Champion, M.F.A., P.O. Box 311 Burlingame, tion and depth of the acetabulum; California 94011; [email protected]. shape of the femoral neck; degree of 121 122 Volume 12, Number 4, 2008 • Journal of Dance Medicine & Science femoral version; and degree of tibial determined that there was less agree- external rotation (HER) data reported version. ment with regards to the assessment by 17 dance-specific studies are listed The hip is a ball and socket joint, of turnout than anticipated. It was in Table 1. Table 2 lists data reported the “ball” referring to the head of the presumed that this would be an op- by the 12 studies that assessed non-hip femur and the “socket” to the acetabu- portunity for the international dance components of turnout (NHCTO). lum. Orientation and depth of the medicine and science community to Table 3 lists data generated by the 15 acetabulum influence the degree of reach a consensus on the measurement studies that reported measurements available TTO.2,10,15 A retro-oriented of turnout, with the goal of standard- of TTO, a measurement inclusive of acetabulum results in greater appear- izing assessment in the near future. It both hip and non-hip components. ance of TTO, while an ante-oriented was quickly determined, however, that The names of authors, the year of acetabulum limits the appearance of this was too large an endeavor to be publication, and a brief description of TTO. A shallow acetabulum allows completed at the time. the sample, measurement procedure for greater hip joint mobility, while Ultimately, the task of performing (including type of motion, testing a deep acetabulum provides greater a detailed and critical review of re- position, and instrumentation or cal- hip joint stability and limits external lated literature evolved to the current culation), sorting variables, and results rotation. authors. Searches were conducted of are included in each table. Studies are The length and shape of the femo- internet databases, bibliographies, catalogued in more than one table if ral neck influences hip range of and reference lists for related research values for more than one measure- motion (ROM) by determining the that generated and published original ment were reported. Evaluation of point at which the neck contacts the data on TO measurement in dancers. these reports will proceed through a acetabulum during external rotation.20 Relevant studies of dance screening brief description of each measurement Long concave femoral necks permit and the assessment of tibial version procedure. increased external rotation ROM in non-dancers were also referenced. of the lower extremity before bony Various methods used to assess TO Hip External Rotation: Table 1 contact with the rim of the acetabu- have unfortunately provided incom- Methods of assessing HER varied. lum occurs. Conversely, shorter and patible and sometimes non-applicable Three positions were used: 1. prone less concave necks decrease external data. While it is generally agreed that with hip extension and knee flexion, rotation of the lower extremity by al- TO results from summative contribu- 2. supine with hip extension and lowing less TO before contact occurs tions of the hip, knee, lower-leg, and knee flexion, 3. sitting with hip and with the acetabular rim. the foot-ankle complex,7,8,11,12,19,20,35 knee flexion. In addition, one study Femoral version is a normal twist clinical measurements of TO often described a unique calculation for in the shaft of the femur. The typi- assess only external rotation of the active “external rotation lag.” A brief cal adult human femur is anteverted hip,36-38 despite research indicating description of measurement methods 6° to 15° along the longitudinal significant contributions of non-hip and results follows. axis.2,4,10,12,21,22 Decreased femoral components ranging between 30% anteversion, or the unusual presence to 48%.6,19,39 Prone: Hip Extension and Knee of femoral retroversion, increases the The purpose of this review is three- Flexion appearance of TTO.7,12,20 fold: to catalogue published reports on Nine studies assessed passive HER Tibial version (TV) is a normal TO in dancers and describe methods (PaHER) in the prone position, with twist in the shaft of the tibia along the of measurement; to evaluate and dis- hip extension and knee flexion, while longitudinal axis in a retroverted direc- play the results; and to make recom- none assessed active HER (AHER) in tion.21,23-28 Average values as reported mendations for future assessment and this position. Variable instrumenta- for samples of the general population research. tion was used: 1. standard goniom- range from 10° to 42°.21,22,24,26-31 Av- eter, as suggested by the American erage values of 10° to 28° have been Literature Review Academy of Orthopaedic Surgeons; reported for samples of dancers.19,32,33 At the time of this review, 24 articles 2. standard goniometer, modified However, normal values ranging from that generated original data on the with a level; or 3. inclinometer. Four 0° to 20° have been referenced in the measurement of TO in dancers were studies are described in further detail dance literature.4,12,15,16,18,20 located (additional procedural articles below: the two studies that reported were found, but are not evaluated the lowest and highest values using a Relevance because they did not report original goniometer, the one study that used This review was initiated in response data). A template was devised during a modified goniometer, and the one to an interactive panel at the 2005 the review process to record specific study that used an inclinometer. International Association for Dance information and to manage inconsis- Standard goniometers were used in Medicine and Science annual confer- tencies in the literature (Fig. 1). Re- seven studies to measure PaHER in ence in Stockholm, Sweden.34 On sults were sorted by measurement, and the prone position.1,14,19,36-38,40 Subjects that occasion the panel of experts are displayed in Tables 1, 2, and 3.