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

Feasibility of mitigating out-toeing gait using compression tights with inward-directing taping lines

Out-toeing gait may cause alterations in lower limb biomechanics that could lead to an increased risk of overuse injuries. Surgery and physical therapy are conventional methods for mitigating such gait, but they are costly and time-consuming. Wearable devices like braces and orthoses are used as affordable alternatives, but they apply non-negligible stress on the skin. Haptic feedback-delivering shoes were also recently developed, but they require actuators and power sources. The purpose of our study is to develop compression tights with inward directing taping lines that apply compression to lower limb muscles and segments to facilitate inward rotation of the foot, overcoming the drawbacks of previous methods. These compression tights were manufactured to fit the average height, leg length, hip girth, and waist girth of South Korean females in their twenties. The efficacy of these compression tights was evaluated by comparing walking kinematics and user satisfaction of 12 female dancers with an out-toeing gait under three conditions: wearing tights with taping lines, tights without taping lines, and basic bicycle shorts. The foot rotation angles and joint kinematics were recorded using a pressure-pad treadmill and motion capture system, respectively. Multiple pairwise comparisons revealed that the compression tights with inward-directing lines significantly reduced foot rotation angles (up to an average of 20.1%) compared with the bicycle shorts (p = 0.002 and 0.001 for dominant and non-dominant foot, respectively) or the compression tights without taping lines (p = 0.005 and p = 0.001 for dominant and non-dominant foot, respectively). Statistical parametric mapping revealed significant main effects of the tight type on joint kinematics. Also, t-tests revealed that the participants reported significantly higher ratings of perceived functionality and usability on the compression tights with inward-directing taping lines. In conclusion, we developed a comfortable and practical apparel-type wearable and demonstrated its short-term efficacy in mitigating out-toeing gait.

Irish Dancing Injuries and Associated Risk Factors: A Systematic Review

Irish dance is growing in popularity, evolving to a more athletic and demanding dance style. The aim of this study is to conduct a systematic review, previously registered with PROSPERO, to identify the prevalence, incidence, and the injury pattern among Irish dancers and analyse the associated risk factors. Six online databases and two dance-specific science publications were searched systematically. Studies were included if the patterns of injuries among Irish dancers were evaluated or the factors associated with injury were analysed, published in English or Portuguese, in peer-reviewed scientific journals. Four reviewers assessed the quality and level of evidence using the Downs and Black criteria and a modified Oxford Centre of Evidence-Based Medicine 2009 model, respectively. Eleven articles were included, eight of Level 3c (cross-sectional) and three of Level 3b (prospective). Mean DB percentage score was 63% ± 7.2%. Prevalence ranged from 72.2% to 92.6%, affecting mostly the foot/ankle complex. Only two articles reported incidence, which ranged from 3.4 to 10.6 injuries/1000 h danced depending on injury definition. Psychological factors, elite level, and insufficient/poor sleep were associated with musculoskeletal injury. Injury prevalence and incidence is high in Irish dancers, with the foot and ankle being more affected. Due to heterogeneity in injury definitions, methods, and populations, along with the need for improvement in studies quality, recommendations were made for future research.

Effect of low back pain on clinical-functional factors and its associated potential risk of chronicity in adolescent dancers of classical ballet: cross-sectional study

BACKGROUND

Low back pain (LBP) is a common symptom in classical ballet dancers, which can limit their daily activities and dance training routines. The purpose of the study was to verify the association and comparison of clinical-functional outcomes (spine flexibility and foot posture) between different levels of intensity low back pain in adolescents of classical ballet and the potential risk of chronicity using the STarT back tool.

METHODS

Cross-sectional study.

PARTICIPANTS

78 adolescent girls who practice classical ballet were evaluated and divided into groups according to level of low back pain: mild (n = 21), moderate (n = 17), and high (n = 20), and a control group (n = 20).

MAIN OUTCOME MEASURES

Pain, flexibility of the spine (thoracic and lumbosacral), risk of chronicity for low back pain, and foot posture were assessed using the visual analogue scale, clinical tests, STarT back screening tool (SBST) questionnaire, and foot posture index (FPI), respectively.

RESULTS

Dancers with high-intensity low back pain showed a potential risk of chronicity by the SBST. The spine pain intensity was not different considering thoracic and lumbosacral flexibility in the sagittal plane, but was different with greater supine FPI when compared to control dancers. Mild low back pain was associated with greater supine FPI. The SBST score was associated with higher exposure time-frequency and time of dancing.

CONCLUSION

Adolescents of classical ballet with high-intensity low back pain showed a potential risk of chronicity by the SBST. The level of intensity low back pain did not influence the clinical-functional aspects of spine flexibility in the sagittal plane, but the level of intensity moderate pain promoted changes in foot posture (more supinated). The potential risk of chronicity using the SBST was also associated with higher exposure time-frequency and time of dancing, in adolescents of classical ballet.

Evaluation of the Correlation Between Flamenco Dance and Ankle and Foot Posture

BACKGROUND

The practice of flamenco dance involves great biomechanical demands, comparable with a high-performance sport. The technical movements of the footwork tap, the jumps, and the turns increase the prevalence of injuries and pathologic disorders of the foot and lower limb. Limited research has examined adaptation of the foot posture and dorsiflexion of the ankle in flamenco dancing. Therefore, the aim of this study was to evaluate whether the practice of flamenco dancing produces modifications in the ankle's dorsiflexion range of motion, Foot Posture Index, or pronation.

METHODS

A cross-sectional observational study with intentional sampling was performed with 26 individuals (52 feet) in two groups: professional female flamenco dancers (n = 13) and nondancers (n = 13). The participants were assessed in a single session for ankle dorsiflexion, foot pronation (navicular drop test), and foot posture (Foot Posture Index).

RESULTS

Significant differences were found between the two groups for left foot Foot Posture Index (P = .007) and right foot navicular drop test (P = .006).

CONCLUSIONS

The results of this study indicate that flamenco dancing can produce modifications in the Foot Posture Index and foot pronation versus nondancers. Further research is required.

Does forced or compensated turnout lead to musculoskeletal injuries in dancers? A systematic review on the complexity of causes

Injury prevalence in dancers is high, and misaligned turnout (TO) is claimed to bear injury risk. This systematic review aimed to investigate if compensating or forcing TO leads to musculoskeletal injuries. A systematic literature review was conducted according to the PRISMA Guidelines using the databases of PubMed, Embase, Emcare, Web of Science, Cochrane Library, Academic Search Premier, and ScienceDirect. Studies investigating the relationship between compensated or forced TO and injuries in all genders, all ages, and levels of dancers were included. Details on misaligned TO measurements and injuries had to be provided. Screening was performed by two researchers, data extraction and methodological quality assessment executed by one researcher and checked by another. 7 studies with 1293 dancers were included. Methodological quality was low due to study designs and a general lack of standardised definition of pathology and methods of assessment of misaligned TO. The studies investigating the lower extremities showed a hip-focus only. Non-hip contributors as well as their natural anatomical variations were not accounted for, limiting the understanding of injury mechanisms underlying misaligned TO. As such no definite conclusions on the effect of compensating or forcing TO on musculoskeletal injuries could be made. Total TO is dependent on complex motion cycles rather than generalised (hip) joint dominance only. Objective dual assessment of maximum passive joint range of motion through 3D kinematic analysis in combination with physical examination is needed to account for anatomical variations, locate sites prone to (overuse)injury, and investigate underlying injury mechanisms.

An analysis of the foot in turnout using a dance specific 3D multi-segment foot model

Introduction

Recent three-dimensional (3D) kinematic research has revealed foot abduction is the strongest predictor of standing functional and forced turnout postures. However, it is still unknown how the internal foot joints enable a large degree of foot abduction in turnout. The primary purpose of this study was to use a dance specific multi-segment foot model to determine the lower leg and foot contributions to turnout that female university-level ballets use to accentuate their turnout.

Methods

Eighteen female dance students (mean age, 18.8 ± 1.6 years) volunteered for this study. Retro-reflective markers were attached to the dancers’ dominant foot. Each dancer performed three repetitions of functional turnout, forced turnout and ten consecutive sautés in first position. Repeated measures ANOVA with Bonferroni adjustments for the multiple comparisons were used to determine the kinematic adjustments, hindfoot eversion, midfoot and forefoot abduction, navicular drop (i.e. lowering of the medial longitudinal arch) and first metatarsophalangeal joint abduction between natural double leg up-right posture and the first position conditions.

Results

Hindfoot eversion (4.6°, p < 0.001) and midfoot abduction (2.8°, p < 0.001) significantly increased in functional turnout compared to the natural double leg up-right posture. Thirteen dancers demonstrated increased first metatarsophalangeal joint (MTPJ) abduction in forced turnout, however no statistically significant increase was found. Navicular drop during sautés in first position significantly increased by 11 mm (p < 0.001) compared to the natural double leg up-right posture.

Conclusion

Our findings suggest dancers do pronate, via hindfoot eversion and midfoot abduction in both functional and forced turnout, however, no immediate association was found between forced turnout and first MTPJ abduction. Foot pronation does play a role in achieving turnout. Further prospective research on in situ measures of the lower limb in turnout and injury surveillance is required to improve our understanding of the normal and abnormal dance biomechanics.

Electronic supplementary material

The online version of this article (10.1186/s13047-019-0318-1) contains supplementary material, which is available to authorized users.

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.

Lower-Leg and Foot Contributions to Turnout in University-Level Female Ballet DancersA Preliminary Investigation

BACKGROUND

Turnout in ballet is produced through summation of the joint structure characteristics and ranges of motion at the hip, knee, ankle, and foot. Contributions of the hip joint to functional turnout in dancers have received extensive examination, whereas little is known about contributions from the knee, ankle, and foot. The aim of this study was to explore the nonhip components of turnout to dancers' functional turnout in first position by assessing passive external tibiofemoral rotation and active measures of foot pronation, ie, navicular drop and Foot Posture Index.

METHODS

Nineteen female university-level dance students aged 16 to 19 years participated in this descriptive correlational study. External tibiofemoral rotation, navicular drop, Foot Posture Index, and functional turnout were measured for the participants' right and left legs.

RESULTS

Regression analyses revealed a weak relationship between passive external tibiofemoral rotation and functional turnout. Correlation analysis revealed a moderate negative relationship between passive tibiofemoral external rotation and the Foot Posture Index in functional turnout.

CONCLUSIONS

These findings suggest that the lower leg does contribute to dancers' overall position of functional turnout. However, current methods are not useful in predicting a dancer's lower-leg contribution and alignment in functional turnout in first position.

The foot posture index in men practicing three sports different in their biomechanical gestures

BACKGROUND

The technical gestures characteristic of certain sports may lead to one type of foot being more prevalent than the others. The Foot Posture Index (FPI) has been used as a diagnostic tool for support postures in various sports, but the differences in these postures between sports of distinct gestures in their actions are far from completely understood.

METHODS

The overall FPI, obtained as the sum of the scores of its six individual criteria, was determined in 90 male athletes (30 runners, 30 basketball players, and 30 handball players) in static bipedal stance and relaxed position. Analysis of variance was used to find significant differences among the three sports in the total FPI and its six criteria.

RESULTS

The mean ± SD FPI was 2.9 ± 2.8 in runners, 3.9 ± 4.1 in basketball players, and -0.4 ± 6.9 in handball players, with significant differences among these groups (P = .008). Significant differences were also found in the talar head position and talonavicular prominence values between handball players and runners (P = .001 and P = .004, respectively) and between handball and basketball players (P = .002 and P = .006, respectively).

CONCLUSIONS

Runners and basketball players had neutral feet, whereas handball players had supinated feet. The differences in foot posture seem to be mainly determined by two of the FPI criteria: talar head position and talonavicular prominence.

Preventing dance injuries: current perspectives

Dancers are clearly athletes in the degree to which sophisticated physical capacities are required to perform at a high level. The standard complement of athletic attributes - muscular strength and endurance, anaerobic and aerobic energy utilization, speed, agility, coordination, motor control, and psychological readiness - all are essential to dance performance. In dance, as in any athletic activity, injuries are prevalent. This paper presents the research background of dance injuries, characteristics that distinguish dance and dancers from traditional sports and athletes, and research-based perspectives into how dance injuries can be reduced or prevented, including the factors of physical training, nutrition and rest, flooring, dancing en pointe, and specialized health care access for dancers. The review concludes by offering five essential components for those involved with caring for dancers that, when properly applied, will assist them in decreasing the likelihood of dance-related injury and ensuring that dancers receive optimum attention from the health care profession: (1) screening; (2) physical training; (3) nutrition and rest; (4) specialized dance health care; and (5) becoming acquainted with the nature of dance and dancers.