Relationship of turnout to hip abduction in professional ballet dancers

Hip Joint Biomechanical Parameters and Their Relationship With the Esthetic Functional Performance of the Développé à la Seconde Movement in Classical Ballet Dancers

Développé à la seconde is a classic ballet movement that requires the maintenance of a high hip joint range of motion (ROM) and muscle strength. However, the contribution of these hip joint biomechanical parameters to this movement's esthetic performance is unclear. Therefore, this study evaluated hip joint biomechanical characteristics of 21 experienced ballet dancers (15-29 y old) and verified the relationship between these variables with the développé à la seconde static and dynamic performance. Correlations between age, ballet practice time, gluteus maximus and gluteus medius thicknesses, ROM, and muscle strength with absolute and relative static and dynamic performances were verified. Flexors, extensors, and internal rotators peak strength and external rotation ROM were highly correlated with absolute and relative static performances (0.5-0.7). Flexors and extensors strength and external and internal rotation ROM showed the highest correlations with the développé dynamic performance (0.49-0.67). Flexor strength and flexor and internal rotation ROM predicted 26% to 41% of this movement's static and dynamic performances. Thus, from a biomechanical perspective, clinical assessment of hip strength and ROM may be used to predict the quality of the ballet dancers' performance of the développé à la seconde and guide classical ballet training.

Deep hip external rotator muscle size in ballet dancers compared to non-dancing athletes, and associations to pain

OBJECTIVES

To compare the deep hip external rotator (DHER) muscle (piriformis, gemelli, quadratus femoris (QF)) cross-sectional area (CSA) in dancers and athletes and evaluate the relationship between DHER size and hip pain.

STUDY DESIGN

Cross-sectional study.

SETTING

Elite ballet and sport.

PARTICIPANTS

33 professional ballet dancers and 33 age and sex-matched athletes.

MAIN OUTCOME MEASURES

CSAs of piriformis, gemelli and QF on magnetic resonance imaging (MRI). Hip pain scored with the Copenhagen Hip and Groin Outcome Score (HAGOS): Hip pain was categorised as 'yes' if HAGOS pain score was <100, 'no' if HAGOS pain was = 100.

RESULTS

Estimated marginal mean CSA of piriformis, gemelli and QF muscles was similar in athletes and dancers (p > 0.05), and CSAs were not associated with hip pain. Male and female dancers had similar sized DHER muscles. In athletes, CSA of piriformis was 55% (p = 0.02, Cohen's d(95%CI) = 0.98 (0.26,1.71)) and the gemelli were 34% (p = 0.03, Cohen's d(95%CI) = 0.98 (0.26,1.70)) larger in men than women; QF was 36% larger (p = 0.08, Cohen's d(95%CI) = 0.77 (0.06,1.48)).

CONCLUSION

Although ballet dancers perform in external rotation, their DHER are no larger than athletes and muscle size was not associated with hip pain.

Hip Instability in Ballet Dancers: A Narrative Review

BACKGROUND

Dancers possess a large degree of hip range of motion that results from a combination of innate and acquired osseous morphology and permissive soft tissues. Generalized hypermobility in dancers may predispose them to a spectrum of hip instability. The objective of this narrative review is to discuss the anatomical characteristics, pathogenesis, risk factors, clinical signs and symptoms, management, and outcomes of hip instability treatments in dancers.

METHODS

A retrospective search was performed beginning November 1, 2017, for English language articles regarding hip stability in the dancer. Key words used included but were not limited to: dance(r), ballet, hip, hypermobility, range of motion, instability, microinstability, and laxity. PubMed, Scopus, and MEDLINE databases were used.

RESULTS

Forty-three studies were analyzed. Groin pain was found to be the most common presenting symptom of hip instability. A variety of impingement and instability signs may be elicited during physical examination. Hypermobility is frequently observed and is thought to be a necessity for participation in elite levels of ballet. Radiographs and advanced planar imaging (magnetic resonance imaging and computed tomography) should be scrutinized to evaluate for dysplasia, cam, pincer, subspine, and rotational morphologies. Dysplasia (low volume acetabulum), cam morphology, femoral retroversion, and coxa valga are common findings in the ballet dancers' hip. Labral injuries and ligamentum teres tears are common and may potentiate instability in the hip. Management options include education, oral non-opioid medications, activity modification, exercise prescription, and surgery. Reported outcomes of these treatments in ballet are limited.

CONCLUSION

Hip hypermobility is prevalent in the ballet population and is a clear advantage. However, it may increase the risk of instability. It is important to identify the multifactorial osseous and soft tissue etiology of hip or groin pain in dancers. Practitioners should have a high level of suspicion for hip instability in the dancer presenting with hip pain and treat accordingly. There is a significant need for increased quantity and quality of investigation into the outcomes of treatment for hip instability in the dancer.

The Dancer's Hip: The Hyperflexible Athlete: Anatomy and Mean 3-Year Arthroscopic Clinical Outcomes

PURPOSE

To report preoperative anatomy, patient-related outcomes measures, and return to dance rates in a cohort of competitive dancers undergoing an arthroscopic hip procedure.

METHODS

Competitive dancers who underwent an arthroscopic hip procedure between 2008 and 2016 were included. Specific types of dance performed, morphology, and radiographic parameters were documented. Outcomes were evaluated with Modified Harris Hip Score (mHHS), the 12-Item Short Form Health Survey, visual analog scale, and Hip Disability and Osteoarthritis Outcome Scores (HOOS).

RESULTS

There were 63 competitive dancers (77 hips) with a mean age 21.2 years in the current study. Specific types of dance performed included 57 studio dance and 41 high-kick dance, and 28 dancers (44%) were professional-level. Morphology included cam-type femoroacetabular impingement (95%), pincer-type femoroacetabular impingement (40%), anterior inferior iliac spine impingement (subspine) (83%), and mild (borderline) dysplasia (11%). Procedures performed included 95% labral repairs, 5% labral debridements, 99% femoral resections, 49% rim resections, 88% subspine decompressions, and 66% capsular plications. At mean 36 months' follow-up post-arthroscopy, the mean outcome improvements were 25.6 points (mHHS), 18.9 points (HOOS-activities of daily living), 29.9 points (HOOS-Sports), 8.7 points (12-Item Short Form Health Survey), and 3.7 points (visual analog scale) (P < .01 for each). Scores were significantly improved from preoperatively to most recent follow-up for mHHS (60.0 vs 85.6 points), HOOS-activities of daily living (72.5 vs 91.5 points), and HOOS-Sports (49.7 vs 79.6) (P < .01). Sixty-three percent of dancers returned to their previous level of competitive dance, 21% returned to limited or modified dance, and 16% were unable to return to dance, including 1 retirement.

CONCLUSIONS

A careful arthroscopic approach to address cam-type pathomorphology, highly prevalent subspine impingement, and capsular laxity in competitive dancers can achieve a modest rate of return to sport and good-to-excellent patient-reported outcomes at short- to mid-term (3-year) follow-up. Eighty-four percent of dancers ultimately returned to competitive dance, although only 63% returned to their preinjury competitive level.

LEVEL OF EVIDENCE

IV, case series.

MRI hip findings in asymptomatic professional rugby players, ballet dancers, and age-matched controls

AIM

To investigate hip magnetic resonance imaging (MRI) findings in asymptomatic professional male rugby players and male ballet dancers compared to age-matched controls.

MATERIALS AND METHODS

After ethics committee approval and consent from participants, 11 professional rugby players, 10 professional ballet dancers, and 10 controls completed activity and symptom questionnaires and underwent 3 T MRI of their self-declared dominant hip. Each scan was independently scored by two musculoskeletal radiologists for multiple features, including: joint morphology, acetabular labrum appearance, cartilage loss, and capsular thickness. Clinical and MRI features were assessed for variance by group using one-way analysis of variance (ANOVA) tests and Tukey post-hoc pairwise comparison of means.

RESULTS

Labral tear prevalence was 87% with no significant difference between groups (p>0.05). Rates of paralabral cysts were significantly higher in ballet dancers (50%), compared to rugby players (0%) and controls (10%; p=0.01). Acetabular cartilage loss was present in 54% with no significant differences between groups. Superior capsular thickness was significantly greater in ballet dancers (5.3 mm) compared to rugby players (3.8 mm) and controls (3.8 mm; p=0.03).

CONCLUSION

Despite the difference in type of activity between groups, there were equally high rates of labral tears and acetabular cartilage loss, questioning the role that sport plays in the development of these findings and their relationship to symptoms. The focally increased superior capsular thickness in ballet dancers may be an adaptive response to extreme ranges of movement.

The Physical Attributes Most Required in Professional Ballet: A Delphi Study

Background It is commonly accepted that dancers are undoubtedly athletes, with ballet perhaps the most demanding dance form. No previous study has sought to define the physical attributes most desired for classical ballet by professional companies and vocational schools. These are likely to include both aesthetic features and attributes that reduce the risk of injury as well as enhance performance. Method An initial survey question using the modified Delphi technique was sent using Opinio Survey Software to a selected international expert panel. This was drawn both from those involved in selection of elite professional ballet dancers, and the international medical professionals involved in the care of dancers. The first questionnaire was open-ended to scope for all the physical attributes most favoured by the professional experts. Results There were 148 responses from the panel of international experts. In total 34 physical attributes were suggested. The 2 most recommended physical criteria for selection into the profession were overall flexibility and overall strength. These results are discussed in the context of the published literature on the mechanics, anatomy and physiology of ballet. Conclusion Flexibility and strength are the 2 features most sought after in elite ballet dancers.

Métodos usados para avaliar o en dehors ou turnout de dançarinos e bailarinos clássicos: revisão da literatura

RESUMO A técnica do ballet clássico exige a realização máxima do en dehors ou turnout, caracterizado pela rotação externa de membros inferiores. Considerando a sua importância, diversos protocolos para a sua avaliação e mensuração têm sido propostos. O objetivo desta revisão foi investigar sistematicamente quais os métodos utilizados para avaliar o turnout de bailarinos clássicos e/ou praticantes de ballet clássico existentes atualmente. A busca foi feita nas bases de dados Scopus, Science Direct e PubMed, no mês de fevereiro de 2016, e os artigos encontrados deveriam: estar redigidos na língua inglesa, avaliar bailarinos clássicos ou dançarinos que praticassem ballet clássico e mensurar o en dehors ou turnout. Foram encontrados 593 artigos, dos quais 25 foram pré-selecionados para esta revisão, apresentando quinze diferentes métodos e instrumentos de mensuração do turnout: cinemetria; inclinômetro; turnout protactor ou transferidor para medir o turnout; goniômetro; Dupuis Tropometer; transferidor original; fotos dos sujeitos; discos rotacionais; teste de flexibilidade de Nicholas; flexímetro; desenho clínico dos pés; sujeito sobre um pedaço de papel ou solo ou quadro branco; ressonância magnética; filmagem do sujeito executando sequência de passos; Dasco Pro Angle Finder. Esta revisão apresenta forte evidência para afirmar que não há, até o presente momento, um método ou instrumento padrão-ouro para mensuração do turnout de bailarinos, de modo que esta costuma ser adaptada e escolhida de acordo com o objetivo de cada estudo.

Influence of turnout on foot posture and its relationship to overuse musculoskeletal injury in professional contemporary dancers: a preliminary investigation

BACKGROUND

The angle of turnout is thought to predispose professional dancers to overuse musculoskeletal injuries of the lower limb; yet, the influence of angle of turnout on foot posture is currently unknown.

METHODS

Twelve professional contemporary dancers (five women and seven men; mean age, 26.8 years) were recruited. The angle of gait and angle of turnout were measured using a quasi-static clinical tracing method. Foot posture was assessed in the base of gait and angle of turnout using the Foot Posture Index. Each dancer completed a dance history and injury questionnaire.

RESULTS

The results show a tendency toward a pronated foot posture (mean, 9°) in the angle of turnout position. A significant relationship was noted between the Foot Posture Index and angle of turnout (ρ = 0.933-0.968, P < .01) and between the number of reported injuries and change in foot posture in the angle of turnout (ρ = 0.789, P < .01) (right foot only). Twenty-eight injuries were reported; male dancers experienced a mean of 2.8 injuries and females a mean of 1.6 injuries. An inverse relationship was noted between age at training initiation and total reported injuries (r =-0.867, P < .01). All of the dancers reported a history of injury to the spine or lower limb, and 9 of the 12 reported an injury within the previous 12 months.

CONCLUSIONS

Turnout is one of the most fundamental aspects of dance technique. This study suggests a trend toward pronation in angle of turnout and a link to lower-limb musculoskeletal injury.

A dance to the music of time: aesthetically-relevant changes in body posture in performing art

In performing arts, body postures are both means for expressing an artist's intentions, and also artistic objects, appealing to the audience. The postures of classical ballet obey the body's biomechanical limits, but also follow strict rules established by tradition. This combination offers a perfect milieu for assessing scientifically how the execution of this particular artistic activity has changed over time, and evaluating what factors may induce such changes. We quantified angles between body segments in archive material showing dancers from a leading company over a 60-year period. The data showed that body positions supposedly fixed by codified choreography were in fact implemented by very different elevation angles, according to the year of ballet production. Progressive changes lead to increasingly vertical positions of the dancer's body over the period studied. Experimental data showed that these change reflected aesthetic choices of naïve modern observers. Even when reduced to stick figures and unrecognisable shapes, the more vertical postures drawn from later productions were systematically preferred to less vertical postures from earlier productions. This gradual change within a conservative art form provides scientific evidence that aesthetic change may arise from continuous interaction between artistic tradition, individual artists' creativity, and a wider environmental context. This context may include social aesthetic pressure from audiences.

Dance-Related Injury

Although dance medicine has derived extensive knowledge from sports medicine, some aspects covered in the practice of dance medicine are unique to this field. Acute and overuse injuries must be analyzed within the scope of associated mechanisms of injury, mainly related to the practice of specific dance techniques. Even though most available medical literature concerning dance medicine is specific to ballet-related conditions, many of the concepts covered here and in other articles can be helpful in the treatment and diagnosis of participants in other dance disciplines. Continued research is expanding the knowledge on injury patterns of different dance disciplines. It is the experience of dance practitioners that dancers are quite in touch with their bodies; thus, when their ailments are systematically analyzed, and underlying cause can usually be identified. In this sense, it is evident that the principles of dance medicine and rehabilitation allow the practitioner to arrive at a diagnosis and treat the underlying causes to prevent reinjury, ameliorate sequelae from injury, and minimize residual deficits after injury.

Range of joint movement in female dancers and nondancers aged 8 to 16 years: anatomical and clinical implications

BACKGROUND

Little data are available on changes that occur with age in joint range of motion in dancers and nondancers.

HYPOTHESIS

In dancers, joint range of motion will increase with age, whereas it will decrease in nondancers, independent of the joint studied.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

The study population included 1320 female dancers, aged 8 to 16 years, who participated in different types of dancing classes (classical ballet, modern dance, jazz, etc) and 226 nondancers of similar age. Range of motion was measured for the hip, knee, ankle, foot, and spinal joints.

RESULTS

The pattern of differences in range of motion with age varied in different joints and types of movement. (1) For combined ankle and foot plantar flexion (pointe), ankle plantar flexion, and hip external rotation, there was no change in range of motion in dancers, whereas range of motion diminished with age in the nondancers. (2) For ankle dorsiflexion, neither group showed any change with age, and range of motion was significantly greater in the nondancer group. (3) For knee flexion, hip flexion, and hip internal rotation, range of motion decreased with age in both groups. (4) For hip abduction, range of motion decreased with age in dancers and remained constant in the nondancers. (5) For hip extension, range of motion increased in both groups. (6) For lower back and hamstrings, range of motion increased among dancers with age and remained constant among nondancers.

CONCLUSION

Dancers and teachers should realize that passive joint range of motion is unlikely to improve with age. Therefore, the major goal of a dancing program should focus on exercises that retain the natural flexibility of the dancers' joints rather than trying to improve them.

An evaluation of differences in hip external rotation strength and range of motion between female dancers and non-dancers

OBJECTIVES

To evaluate the differences in hip external rotation (ER) strength and inner, outer, and total hip ER range of motion (ROM) between dancers and non-dancers and between left and right sides in each group.

METHODS

Seventy one subjects (34 dancers and 37 non-dancers) volunteered for this study. The strength (truncated range average torque (TRAT), work, and angle specific torque (AST)) of the hip external rotator muscle group, through the full available active hip ER ROM, was evaluated using concentric isokinetic (30 degrees /s) testing on a KinCom dynamometer. Adjustment for lean body mass (LBM) was made for comparison of strength between groups. A two way repeated analysis of covariance was used to compare strength between groups. A two way repeated analysis of variance was used to compare strength between sides and ROM between groups and sides. Bonferroni correction was made for multiple analyses, and significance was accepted at p<or=0.05.

RESULTS

AST at 0 degrees , 20 degrees , 30 degrees , and 40 degrees of hip ER was greater in the dancers than the non-dancers (p<or=0.022). TRAT, work, AST(0 degrees ), AST(20 degrees ), and AST(30 degrees ) of hip ER were all greater on the right side than the left (p = 0.007) in both groups. Dancers had greater inner ER ROM (p = 0.013) and less outer ER ROM than non-dancers (p<or=0.001). There was no difference in total ER ROM between groups (p = 0.133). The right side had greater inner ER (p<or=0.001) and total ER ROM (p<or=0.001) than the left in both groups.

CONCLUSIONS

Ballet dancers have greater inner range, angle specific strength and inner range ER ROM, demonstrated by a shift in the dancers' strength curves. This shift in the strength curve towards the inner range of hip ER may be an adaptive training response.

Patellofemoral pain in female ballet dancers: correlation with iliotibial band tightness and tibial external rotation

Review of the literature reveals that ballet dancers have a high incidence of idiopathic patellofemoral pain. Twenty-four female ballet dancers were subjects in a study of the relationship between: 1) iliotibial band (ITB) tightness and patellofemoral pain, and 2) ITB tightness and degrees of tibial external rotation used in the dance demi-plie. Dancers were initially assessed by questionnaire to determine if any had knee pain. Twelve subjects met the study criteria for patellofemoral pain, and 12 dancers without knee pain served as controls for the study, Iliotibial band tightness was measured (Ober test), and degrees of tibial external rotation used during knee flexion (demi-plie) in standing were measured in both legs of all 24 subjects (48 legs). Chi-square analysis of the collected data revealed that there was an association between ITB tightness and patellofemoral pain in the dancers. Data analysis using the Wilcoxon Rank Sum test revealed that the degree of tibial external rotation used by dancers with iliotibial band tightness was significantly greater than those without ITB tightness. This study confirms the assumption that ITB tightness in dancers may be a contributing factor to patellofemoral pain. Follow-up study is indicated to determine if the preservation or restoration of functional ITB length is effective in the prevention and/or treatment of patellofemoral pain in ballet dancers.