title: Femoral Shaft Torsion in Injured and Uninjured Ballet Dancers and Its Association with Other Hip Measures: A Cross-sectional Study.
abstract: Low range femoral torsion, termed "lateral shaft torsion," has been associated with greater range of hip external rotation and turnout in dancers. It is also hypothesized that achieving greater turnout at the hip minimizes torsion at the knee, shank, ankle, and foot, and consequently reduces incidence of lower limb injuries. The primary aims of this study were to investigate: 1. differences in range of femoral shaft torsion between dancers with and without lower limb injuries; and 2. the relationship between femoral shaft torsion, hip external rotation range, and turnout. A secondary aim was to examine the relationship between femoral shaft torsion and other hip measures: hip strength, lower limb joint hypermobility, hip stability, and foot progression angle, as explanatory variables. Demographic, dance, and injury data were collected, along with physical measures of femoral shaft torsion, hip rotation range of motion, and turnout. Hip strength, control, lower limb hypermobility, and foot progression angle were also measured. Eighty female dancers, 50 with lower limb injury (20.7 ± 4.8 years of age) and 30 without lower limb injury (17.8 ± 4.1 years of age), participated in the study. There was no difference in range of femoral shaft torsion between the groups (p = 0.941). Femoral shaft torsion was weakly correlated with range of hip external rotation (r = -0.034, p = 0.384) and turnout (r = -0.066, p = 0.558). Injured dancers had a significantly longer training history than non-injured dancers (p = 0.001). It was concluded that femoral shaft torsion does not appear to be associated with the overall incidence of lower limb injury in dancers or to be a primary factor influencing extent of turnout in this population.
authors.affiliation: Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Sydney, Australia.
authors.forename: Eliza
authors.initials: E
authors.lastname: Hafiz
authors.affiliation: Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Sydney, Australia; Faculty of Health Sciences, The University of Sydney, 75 East Street, Lidcombe NSW 2141 Australia. claire.hiller@sydney.edu.au.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Hiller
authors.affiliation: Discipline of Biomedical Sciences, School of Medical Sciences, The University of Sydney, Sydney Australia.
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Nicholson
authors.affiliation: Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Sydney, Australia.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Nightingale
authors.affiliation: Physiotec Physiotherapy, Tarragindi, Brisbane, Australia.
authors.forename: Alison
authors.initials: A
authors.lastname: Grimaldi
authors.affiliation: Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Sydney, Australia.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Refshauge
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D003615:Dancing / Q000293:injuries*; D018483:Diaphyses / Q000293:injuries; D005260:Female; D005269:Femur / Q000293:injuries*; D025981:Hip Injuries / Q000209:etiology*; D006801:Humans; D016059:Range of Motion, Articular; D012016:Reference Values; D012399:Rotation; D055815:Young Adult