Comparison of postural stability between injured and uninjured ballet dancers

The Effects of Pointe Shoes on Ballet Dancers' Biomechanics, Muscle Activity, Movement and Symptoms: A Scoping Review

Introduction: Dancing en pointe requires ballet dancers to stand on the tips of their toes while wearing a structured pointe shoe. Understanding the effect of pointe shoes on ballet dancers' biomechanics, function, symptoms and skin health is essential to guide shoe development and ultimately improve dancer performance. Therefore, the purpose of this scoping review was to map the evidence and identify knowledge gaps related to the effect of wearing pointe shoes on professional and recreational ballet dancers. Method: A scoping review was conducted by searching 6 electronic databases and the International Association for Dance Medicine and Science Bibliography. Results: Thirty-five studies were grouped into 5 categories: pointe shoe factors (eg, toe box and shank, pointe shoe status; 9 studies), shoe types (eg, flat shoes vs demi pointe vs pointe; 10 studies), ballet movements (11 studies), symptoms (5 studies), and intrinsic dancer factors (eg, foot type/toe length; 7 studies). Studies were published between 1979 and 2023, with 72% (n = 23) published between 2006 and 2020. Most (86%) of the studies were cross-sectional. Most studies explored biomechanical outcomes and the most common data collection device was force plates (19 studies). Overall, there was an insufficient volume of evidence for specific research aims. Significant gaps in knowledge exist regarding functional and performance-based outcomes, injury outcomes including exploration of factors such as shoe age/usage, and pointe shoe treatment factors. Conclusions: Currently the field of research suffers from threats to ecological validity, with many study methods not reflecting ballet-specific demands or environments. The impact of pointe shoes on ballet dancers is a developing research area, and this scoping review can help guide future research decisions. Studies need to target the knowledge gaps and employ rigorous ecologically valid study designs and ensure that findings inform shoe design and dancer education to minimize injury and maximize comfort and performance.

Weighting of visual and auditory inputs in dancers with and without previous ankle injury

Elite dance requires highly controlled balance performance in dynamic visual and auditory environments characterized by the use of stage lighting and music. Perturbing visual input is known to influence balance in dancers, but the effects of sounds have not been clearly established. Ankle inversion injuries are common in dancers and may also play a role in dancers' ability to respond to sensory perturbations. The aims of this study were to identify changes in static balance in response to visual or auditory perturbation in elite collegiate dancers with and without a history of ankle injury, and to describe coupling of measurements obtained from the waist and head during balance. Thirty-seven dancers: 22 controls and 15 with a history of ankle sprain, performed single-leg balance under static and dynamic visual and auditory conditions. Dancers demonstrated increased waist sway when viewing a dynamic visual scene and when presented with moving sounds and increased head sway with dynamic visuals. These results did not vary by history of ankle sprain. While dancers appear to dampen the impact of waist sway on head motion during single leg stance, even highly trained dancers may experience challenges controlling balance under perturbing visual and auditory conditions like those present during stage performance.

A comparison of the range of motion and dynamic stability of the ankle joint of athletes with an ankle sprain as compared to healthy controls: A cross-sectional study

Background

Ankle sprains are the most common lower-leg musculoskeletal injuries, frequently occurring among athletes and other physical activity individuals. The objective of this study was to compare the ankle range of motion and dynamic stability of healthy and injured athletes for their dominant and nondominant legs.

Methods

A cross-sectional study design was selected to investigate this study with 32 male soccer players with average age: 22.6 ± 3.3 years, weight: 69.6 ± 5.7 kg, height: 176.8 ± 5.32 cm, with a history of a lateral ankle sprain on the dominant leg for the past 2 years. Ankle range of motion was determined using dorsiflexion and plantar flexion by a goniometer. The dynamic stability was determined using the SWAY medical system. An independent t-test was used to study the differences between healthy and injured groups and between dominant and nondominant legs for dynamic stability, dorsiflexion, and plantar flexion range.

Results

There were higher significant differences for dynamic stability in healthy participants than in injured participants for their dominant (P = 0.001) and nondominant (P = 0.001) legs. There were significant differences in dynamic stability in the dominant and nondominant leg (healthy [P = 0.033] and injured [P = 0.000] participants). The dominant leg shows higher dynamic stability in healthy group, whereas nondominant leg shows higher dynamic stability in the injured group.

Conclusion

The study found significant differences between the injured and sound legs. The injured dominant and nondominant leg revealed a striking disparity in the ankle range of motion. Therefore, the study demonstrated that ankle sprain causes due to less stability of the ankle joint, which limits ankle movements.

Effects of a specific injury prevention neuromuscular training program for young female dancers. A randomized-controlled trial

To assess the effects of a specific injury prevention neuromuscular training programme (IPP) on balance and lower-limb asymmetry in female competitive dancers (age 12-20 years; height 1.57 ± 0.06 m; weight 24.27 ± 2.79 kg) were randomly allocated to an active general control (GIPP, n = 7) and specific (SIPP n = 7) group. Both programmes were conducted for 6 weeks, with a frequency of three sessions per week. Dynamic balance and lower-limb asymmetry were assessed before and after the intervention. A greater improvement in right-leg total balance (86.6[84.0-90.5] vs 93.8[86.7-99.4];p = 0.035), left-leg total balance(87.8[81.0-89.1] vs 93.6[90.6-100.0];p = 0.013), left-leg anterior balance (71.9[69.1-72.2] vs 74.6[72.0-77.3];p = 0.041), left-leg posteromedial balance (80.5[72.9-83.3] vs 85.9[83.0-94.0];p = 0.048), and left-leg posterolateral balance (79.5[70.4-84.5] vs 85.0[80.0-88.5];p = 0.048) was observed in the SIPP group compared to the GIPP group. No other significant intra-group changes nor inter-group differences were noted. Therefore, compared to a GIPP, a SIPP induced greater improvements in lower-limb dynamic balance in female dancers, potentially leading to greater reduction in lower-limb injury risk.

Recovery from an unexpected standing-slip in professional ballet dancers

Although interventional studies have suggested that dance-based training may reduce fall risk for older adults based on unperturbed assessments, it remains unknown whether dance (particularly ballet) enhances recovery from an external perturbation. This preliminary study sought to test if and how ballet dancers respond differently to a novel standing-slip perturbation relative to non-dancers. Ten young professional ballet dancers and 10 age/sex-matched non-dancers were exposed to an unannounced slip while standing on the treadmill. Their reactions to the slip, characterized by dynamic gait stability (primary outcome), and the recovery stepping and trunk movements (secondary outcomes), were compared between groups. No significant group difference in dynamic gait stability was found at slip onset and recovery step liftoff, but dancers were more stable than non-dancers at touchdown (p = 0.046). Compared to non-dancers, dancers took a longer (p = 0.049) and faster (p = 0.007) backward recovery step and exhibited a less backward leaned trunk at all instants (p ≤ 0.026). Our study suggests that professional ballet dancers are more stable after a novel standing-slip than non-dancers. This better slip-related fall resistance among dancers could result from their more effective recovery stepping strategy and better trunk movement control after the slip. Both reactions may be attributed to ballet training, which requires frequent backward stepping and an upright trunk. Our findings could potentially provide preliminary evidence for applying ballet training to reduce balance losses and falls in people at a high fall risk. More studies are needed to examine ballet training's effects among other populations with elevated fall risk in real-life situations.

Sensing Technology for Assessing Motor Behavior in Ballet: A Systematic Review

Background

Human performance in classical ballet is a research field of growing interest in the past decades. Technology used to acquire data in human movement sciences has evolved, and is specifically being applied to evaluate ballet movements to better understand dancers’ profiles. We aimed to systematically review sensing technologies that were used to extract data from dancers, in order to improve knowledge regarding the performance of ballet movements through quantification.

Methods

PubMed, MEDLINE, EMBASE, and Web of Science databases were accessed through 2020. All studies that used motor control tools to evaluate classical ballet movements, and possible comparisons to other types of dance and sports movements were selected. Pertinent data were filled into a customized table, and risk of bias was carefully analyzed.

Results

Eighty studies were included. The majority were regarding classical ballet and with pre-professional dancers. Forty-four studies (55%) used two or more types of technology to collect data, showing that motion capture technique, force plates, electromyography, and inertial sensors are the most frequent ways to evaluate ballet movements.

Discussion

Research to evaluate ballet movements varies greatly considering study design and specific intervention characteristics. Combining two or more types of technology may increase data reliability and optimize the characterization of ballet movements. A lack of studies addressing muscle–brain interaction in dancers were observed, and given the potential of novel insights, further studies in this field are warranted. Finally, using quantitative tools opens the perspective of defining what is considered an elite dancer.

Body asymmetries as risk factors for musculoskeletal injuries in dancesport, hip-hop and ballet dancers?

OBJECTIVES

The study aimed to determine the incidence and expression of body asymmetries in dancers of three different dance styles: dancesport (n = 14), hip-hop (n = 21) and ballet (n = 20) and to examine how body asymmetries (muscle strength and power, stability and range of motion) are associated with musculoskeletal injuries occurring over the past 12 months.

DESIGN

Cross-sectional and retrospective study.

METHODS

Maximal isometric voluntary contraction was measured for trunk, hip, knee and ankle movements. Participants performed a single leg stance, unilateral landing, weight bearing symmetry, squat and countermovement jump on force platforms. Passive range of motion was measured for hip, knee and ankle with two-arm goniometer or digital inclinometer (hip flexion, extension and rotations). A retrospective questionnaire was used to collect data on musculoskeletal injuries occurring in the last 12 months.

RESULTS

Different dance styles were associated with different body asymmetries, including strength asymmetries (hip flexion and external rotation), agonist/antagonist asymmetries (trunk flexion/extension, hip abduction/adduction, ankle dorsi/plantar flexion) and hip adduction and internal rotation range of motion asymmetries. Moreover, strength asymmetries of hip flexion, adduction and abduction/adduction as well as stability asymmetries were associated with the total number of musculoskeletal injuries.

CONCLUSIONS

The incidence of body asymmetries (> 10%) in dancesport, hip-hop and ballet dancers was confirmed, as well as the association of some asymmetries with self-reported injuries occurring over the last 12 months. The cause-effect relationship should be clarified by further studies.

Applications of Biomechanical Foot Models to Evaluate Dance Movements Using Three-Dimensional Motion Capture: A Review of the Literature

Dance movement requires excessive, repetitive range of motion (ROM) at the foot-ankle complex, possibly contributing to the high rate of injury among dancers. However, we know little about foot biomechanics during dance movements. Researchers are using three-dimensional (3D) motion capture systems to study the in vivo kinematics of joint segments more frequently in dance-medicine research, warranting a literature review and quality assessment evaluation. The purpose of this literature review was to identify and evaluate studies that used 3D motion capture to analyze in vivo biomechanics of the foot and ankle for a cohort of dancers during dance-specific movement. Three databases (PubMed, Ovid MEDLINE, CINAHL) were accessed along with hand searches of dance-specific journals to identify relevant articles through March 2020. Using specific selection criteria, 25 studies were identified. Fifteen studies used single-segment biomechanical foot models originally created to study gait, four used a novel two-segment model, and six utilized a multi-seg- ment foot model. Nine of the studies referenced common and frequently published gait marker sets and four used a dance-specific biomechanical model with purposefully designed foot segments to analyze the dancers' foot and ankle. Description of the biomechanical models varied, reducing the reproducibility of the models and protocols. Investigators concluded that there is little evidence that the extreme total, segmental, and inter-segmental foot and ankle ROM exerted by dancers are being evaluated during dance-specific movements using 3D motion capture. Findings suggest that 3D motion capture is a robust measurement tool that has the capability to assist researchers in evaluating the in vivo, inter-segmental motion of the foot and ankle to potentially discover many of the remaining significant factors predisposing dancers to injury. The literature review synthesis is presented with recommendations for consideration when evaluating results from studies that utilized a 3D biomechanical foot model to evaluate dance-specific movement.

Gait Biomechanics and Balance Associate with Talar and Subtalar T1ρ Relaxation Times in Those with Chronic Ankle Instability

PURPOSE

This study aimed to determine associations between T1ρ relaxation times of talar and subtalar articular cartilage and commonly altered gait biomechanics and postural control outcomes in those with chronic ankle instability (CAI).

METHODS

Fifteen individuals with CAI (21.13 ± 1.81 yr) completed a T1ρ magnetic resonance imaging as well as a postural control and an overground gait assessment. Talocrural and subtalar cartilage was segmented manually to calculate T1ρ relaxation times. Greater T1ρ relaxation times were interpreted as decreased proteoglycan content. Pearson product-moment bivariate correlations examined the relationships between T1ρ relaxation times and the gait biomechanics and postural control outcomes.

RESULTS

Across multiple variables, worse postural control demonstrated moderate to strong associations (range, 0.433-0.642 and -0.713) with greater talar T1ρ relaxation times. At the subtalar joint, greater T1ρ relaxation times were associated with lower peak vertical ground reaction forces, lower average vertical ground reaction force loading rates, and lower peak loading rates (range, -0.438 to -0.622). At the talar dome, greater talar T1ρ relaxation times were associated with increased knee extensor moments (r = 0.457), as well as greater knee flexion (r = 0.482) and knee adduction (r = 0.407) at initial contact. Larger step spatiotemporal gait parameters also associated with greater talar and subtalar T1ρ relaxation times (range, 0.434-0.697).

CONCLUSIONS

In individuals with CAI, worse postural control and altered kinematic, kinetic, and spatiotemporal outcomes demonstrate moderate to strong associations with greater talar T1ρ and/or subtalar relaxation times (i.e., less proteoglycan content). Associations between modifiable neuromechanical variables and greater T1ρ relaxation times may represent potential therapeutic interventions to mitigate ankle joint degeneration in those with CAI.

The effect of latin dance on dynamic balance

BACKGROUND

Figures and movements in Latin dance are effectively used to provide posture stabilization and balance control. A Computerized Dynamic Posturography can be used to complete a functional evaluation of postural control and stability in static and dynamic conditions, mediated by the interaction between the visual, vestibular, and somatosensory systems.

RESEARCH QUESTION

According to the results of Computerized Dynamic Posturography, do dancers have better postural control and stability when compared to non-dancers, and can dance activity be recommended for vestibular rehabilitation?

MATERIAL AND METHODS

Our study included 26 professional Latin dancers and 26 non-dancers as a control group whoboth had no problems with their hearing or balance. Pure-tone audiometry and Computerized Dynamic Posturography tests were applied to the participants. The test results for the professional dancers and the control group were compared and evaluated. In statistical analysis, the Mann-Whitney U and Independent Samples T tests were used. A value of p < 0.05 was accepted for significance.

RESULTS

According to the results of the Computerized Dynamic Posturography, the dancers generally performed better than the control group. While statistically significant and better performances were observed in dancers in terms of the composite balance, visual and vestibular scores within the scope of the Sensory Organization Test (p < 0.05), no statistically significant difference was found for somatosensory and preference scores (p > 0.05). Also, significant differences were obtained between the two groups in some subtests of Adaptation, Unilateral Stance and Limits of Stability assessment (p < 0.05). No significant difference was observed in Rhythmic Weight Shift results (p > 0.05).

IMPORTANCE

The results of thisresearch demonstrate that balance and posture improve through dance. Therefore, adding appropriate dance activities to vestibular rehabilitation programmes might be helpful.

Postural analysis in female Bharatanatyam dancers: a cross-sectional study

Background

Gaining proficiency in Bharatanatyam dance form necessitates maintenance of different postures for prolonged duration. These repetitive movements place tremendous physical demands on the body at young age and may alter the postural profile of the dancer. The study aimed to evaluate the differences in terms of posture between female Bharatanatyam dancers and age-matched non-dancers. A cross-sectional study was conducted in 40 female Bharatanatyam dancers and 40 age-matched female non-dancers in the age group of 18 to 30 years. Analysis of erect standing posture of dancers and non-dancers was conducted in a reserved environment using a photogrammetric method. Static photographs of the subjects were taken in the sagittal plane. The measurement of the angles of the digitized photographs was performed using KINOVEA 0.8.15 software. Head protrusion angle, cervical lordosis angle, thoracic kyphosis angle, lumbar lordosis angle, and pelvic tilt angle were evaluated.

Results

There was no significant difference between the dancers and non-dancers with respect to head protrusion angle (p = 0.081), cervical lordosis (p = 0.15), and thoracic kyphosis (p = 0.33). Significant differences were identified between the dancers and non-dancers for lumbar lordosis (p = 0.00) and pelvic tilt (p = 0.00) using independent t test with dancers. Higher values of lumbar lordosis and pelvic tilt were observed in dancers.

Conclusion

Increased lumbar lordosis and anterior pelvic tilt were observed in Bharatanatyam dancers as compared to non-dancers. Hence, it is vital to establish preventive measures like postural re-education, muscular balance, and flexibility to prevent erroneous postural patterns capable of causing pain and injuries.

Risk Factors for Lower-Extremity Injuries in Female Ballet Dancers: A Systematic Review

BACKGROUND

Ballet dancers have a high prevalence of injuries to the lower extremity. Many studies have investigated the relationship between dance injury and risk factors. However, risk factors for lower-extremity injury comparing recreational- and elite-level ballet dancers are scarce.

OBJECTIVE

To systematically review available original studies to assess risk factors for lower-extremity injury in female ballet dancers between recreational and elite ballet dancers.

DATA SOURCES

Five online databases [Web of Science, PubMed, OVID (Medline), EBSCO, and ProQuest] were searched systematically.

STUDY SELECTION

Included studies had an analytic study design published in the past 11 years and investigated an association between potential risk factors and lower-extremity injury in female ballet dancers.

STUDY APPRAISAL

Assessed independently by 2 reviewers using the Downs and Black (DB) criteria and Oxford Centre of Evidence-Based Medicine.

RESULTS

Seventeen studies were included. Alignment was a risk factor for lower-extremity injury in both recreational and elite ballet dancers. In elite ballet dancers, poor lumbopelvic movement control, inappropriate transversus abdominis contraction, decreased lower-extremity strength, and poor aerobic fitness were risk factors for lower-extremity injury. In recreational ballet dancers, hypermobility of the hip and ankle and longer training hours were risk factors for lower-extremity injury. Mean DB score was 15.94 (SD 1.57). The majority of studies were retrospective cohort studies or had poor follow-up, with 7 level 2b studies, 6 level 3b studies (cross-sectional), and 4 level 1b studies (prospective cohort with good follow-up).

CONCLUSIONS

Alignment was identified as a common risk factor for recreational and elite ballet dancers. Other risk factors differed between recreational ballet dancers and elite ballet dancers. Future studies are warranted to use a prospective study design, identify dance level-specific risk factors, and implement evidence-based prevention strategies.

Differences in Balance Ability and Motor Control between Dancers and Non-Dancers with Varying Foot Positions

The purpose of this study was to investigate balance and motor control in dancers and non-dancers with different foot positions. Physically active female dancers (n = 11) and non-dancers (n = 9) randomly completed two balance tests in a single visit: 1) Y-balance test (YBT), and 2) motor control test (MCT). Each test was completed with two different foot positions: 1) first ballet position in which heels were touching and feet were externally rotated to 140 degrees, and 2) sixth ballet position in which heels were spaced 10 cm apart and forward parallel. For the YBT, participants completed three attempts at anterior, posteromedial, and posterolateral reaches, which were averaged and standardized to limb length for a composite score. For the MCT, participants completed a multi-directional target test on a Biosway balance system, and accuracy and time to completion were analyzed. Findings revealed no differences in YBT score (p = 0.255), MCT score (p = 0.383), or MCT time (p = 0.306) between groups in the sixth position. However, dancers displayed better YBT scores (p = 0.036), MCT scores (p = 0.020), and faster MCT times (p = 0.009) in the first position. Results suggest that superior balance and motor control in dancers may be limited to less innate dance-specific foot positions.

The Relationship Between Postural Stability, Anthropometry Measurements, Body Composition, and Sport Experience in Judokas with Visual Impairment

Background: Postural stability is quite mandatory when practicing high-performance sports. Investigations of postural stability and related variables in judokas with visual impairment can lead to new training plans targeting the improvement of postural stability and ultimately to enhanced performance. Objectives: To investigate postural stability and its relationship with anthropometric measurements, body composition, and experience in judokas with visual impairment. Methods: Seventeen judokas (70.6% men) with visual impairment participated in this cross-sectional study. The athletes were grouped based on the functional classification of partial (B2/B3, n = 10) and total visual impairment (B1, n = 7). Postural stability was assessed using the elliptical area of the 95% confidence interval (Area) and the average displacement velocity (Vavg) while remaining in a bipedal stance with eyes closed and blindfolded. Body mass, height, circumferences, skinfold thickness and diameters were measured and used to estimate body composition. Between-group comparisons were evaluated using the Mann-Whitney test. Bivariate correlations were determined with Spearman’s correlation coefficient with bootstrap analysis and 95% confidence interval (95% CI) from 500 resamplings. Results: No significant difference was observed between the B1 and B2/B3 groups in relation to postural stability (Area; P = 1.00; Vavg; P = 0.85). Postural stability (Area but not Vavg) correlated positively and moderately (P < 0.05) with anthropometric measurements and negatively with judo experience (practice time). Conclusions: The postural stability of judokas was unrelated to the degree of visual impairment. Postural instability was correlated with anthropometric measurements, mainly body fat and height, and judo experience.

Evaluation of Professional Ballet Dancers Body Posture During Barre Movements

Ballet dancers have finite careers due to the demands placed upon their bodies throughout years of training, study, and performance. The average age a dancer retires is 34 due to persistent stress on their joints and injuries due to mechanical overload or overuse. Proper form is crucial to prevent injury. The aim of this study was to establish benchmarks for normal movement patterns among professional dancers. Ten professional ballerinas were studied. Reflective markers were placed on the pelvis, left and right anterior superior iliac spine (ASIS), and posterior iliac spine (PSIS) to evaluate motion during Barre movements: plié, grand battement, and développé. Pelvis flexion/extension, mediolateral rotation, and torsion were analyzed. These motions test different skills. The plié is a controlled coordinated motion using both legs. The grand battement and développé both require leg extension, one with a quick motion that creates momentum and one using controlled motion that requires strength. Each requires core and pelvis stability to perform accurately and with less injury. Dancers' motions were consistent. Maximum pelvis range of motion for the plié, grand battement, and développé were 8.0, 42, and 50 deg, respectively. This represents usable benchmarks with which other dancers may be compared, for example, those who are at different levels of training, injured, predisposed to injury, or recovering from injury. Early recognition of pathologic movement patterns could benefit professional and amateur dancers by helping to prevent injuries, and potentially improve the quality and length of their careers.

The physical features suitable for classical ballet training

OBJECTIVE

The aim of this study was to determine the prerequisite physical features of classical ballet education.

METHODS

Students who enrolled and were rejected for the applications of State Conservatory Ballet Main Art Branch in the academic year 2013-2014 and 2014-2015 were compared with their exam results. This study involves defining the physical ability and determining physical fitness by using Eurofit tests including the Flamingo Balance test (FB), Plate Tapping (PT), Sit and Reach (SITR), Standing Broad Jump (SBJ), Handgrip test (HG), Sit Up in 30 Seconds (SU) and Shuttle Run 10 × 5 meter (SR), Heath-Carter somatotyping method and anthropometric measurements which determine ballet students' body type and physical abilities. Sixty-nine girls between 8-11 years old who applied for ballet education at the State Conservatory Ballet Main Art Branch were included in the study. While the average of age, height and weight measurements of enrolled students were 9.40 ± 0.74 year, 1.38 ± 0.08 m and 30.03 ± 4.73 kg respectively, the same dimensions were found in rejected students, i.e. 9.79 ± 0.94 year, 1.40 ± 0.10 m and 35.59 ± 7.31 kg respectively.

RESULTS

Measurements of diameter, circumference and subcutaneous fat were lower (p< 0.05) for enrolled students. The major body type of enrolled students was identified as mesomorphy, whereas the major body type of rejected students was identified as endomorphy. All dimensions of the Eurofit tests, except the strength test, were significantly different in enrolled students (p< 0.05).

CONCLUSIONS

The parameters used in this study can be convenient in objectively evaluating classical ballet education.

Effects of Textured Balance Board Training in Adolescent Ballet Dancers With Ankle Pathology

CONTEXT

Ankle sprains are common among adolescent ballet dancers and may be attributed to inadequate ankle proprioception. Thus, a short period of training utilizing proprioceptive activities requires evaluation.

OBJECTIVE

To assess training conducted for 3 or 6 weeks on a textured-surface balance board using ankle proprioception scores for ballet dancers with and without chronic ankle instability, and with and without previous ankle sprain (PAS).

DESIGN

Intervention study.

SETTING

The Australian Ballet School.

PARTICIPANTS

Forty-two ballet dancers, aged 14-18 years.

INTERVENTIONS

Dancers randomized into 2 groups: group 1 undertook 1 minute of balance board training daily for 3 weeks; group 2 undertook the same training for 6 weeks.

MAIN OUTCOME MEASURES

Preintervention, Cumberland Ankle Instability Tool questionnaire data were collected, and PAS during the last 2 years was reported. Active ankle inversion movement discrimination ability was tested immediately pre and post intervention and at 3 and 4 weeks.

RESULTS

Ankle discrimination acuity scores improved over time for both groups, with a performance decline associated with the early cessation of training for group 1 (P = .04). While dancers with PAS had significantly worse scores at the first test, before balance board training began (P < .01), no significant differences in scores at any test occasion were found between dancers with and without chronic ankle instability. A significantly faster rate of improvement in ankle discrimination ability score over the 4 test occasions was found for dancers with PAS (P = .002).

CONCLUSIONS

Three weeks of textured balance board training improved the ankle discrimination ability of ballet dancers regardless of their reported level of chronic ankle instability and at a faster rate for dancers with PAS. Previous ankle sprain was associated with a lower level of ankle discrimination ability; however, following 3 weeks of balance board training, previously injured dancers had significantly improved their ankle discrimination acuity scores.

Standing balance of professional ballet dancers and non-dancers under different conditions

Ballet training has been reported to positively influence balance ability. It is not entirely clear how improved balance ability manifests under standing conditions with different demands on postural control. The aim of the study was to compare balance of ballet dancers and non-dancers in a unipedal stance under different conditions. Twenty-five professional ballet dancers and twenty-five controls completed four unipedal standing balance tests: firm surface with eyes open and closed; foam mat surface with eyes open; and firm surface with eyes open immediately after performing ten 360° whole-body turns. The centre of pressure (COP) data were obtained with a force platform and the direction-specific standard deviations, velocities, and sample entropy of the COP displacement were computed. A three-way analysis of variance was used to compare groups, genders, and conditions. For standing immediately after performing ten turns, the postural sway parameters were significantly larger in the control group compared to the ballet dancers in both men and women. In this stance condition the values of postural sway and COP velocities in the control group were larger in the men compared to the women. For both genders in the control group all postural sway and COP velocity parameters were larger in standing with eyes closed and standing after performing 10 turns compared to standing with eyes open on both firm and foam surface. In the ballet dancers all COP velocity parameters were larger in standing with eyes closed compared to all other conditions. The results from the present study indicate that professional ballet dancers do not have a better general balance ability than untrained subjects.

Effect of Pilates Intervention on Physical Function of Children and Youth: A Systematic Review

OBJECTIVE

To conduct a systematic review to evaluate the effectiveness of Pilates intervention on physical function in children and youth.

DATA SOURCES

Six electronic databases were searched from inception to June 2018 using the term Pilates.

STUDY SELECTION

Articles were included if they (1) reported original data for a Pilates-only intervention; (2) involved children or youth aged up to 22 years; (3) reported a musculoskeletal, pain, or function study outcome. Searches identified 2565 papers and 11 studies fulfilled the inclusion criteria.

DATA EXTRACTION

The 2 authors independently screened and assessed all studies and any discrepancies were resolved by consensus.

DATA SYNTHESIS

Level of evidence was classified using the Oxford Centre for Evidence Based Medicine. Study quality was assessed using the Physiotherapy Evidence Database for randomized controlled trials and Risk of Bias in N-of-1 Trials scale for single case experimental design studies. Four studies were high quality, 3 were fair quality, and 4 were of low quality. Findings showed that Pilates does appear to improve flexibility (n=6); muscle strength, power and movement speed (n=3); postural control, orientation and balance (n=3); metabolic cost (n=1); functional ability (n=1) and health related quality of life (n=1) and reduce pain (n=2) in children with musculoskeletal pathology, the majority with a large effect size. Pilates content varied from group-based mat classes to individualized programs using specialized equipment. Intervention dose and frequency varied widely.

CONCLUSIONS

This is the first systematic review of the effect of Pilates intervention for children and youth. Research is in the preliminary stages; however, Pilates does appear to improve flexibility, strength and postural control, and reduce pain in children with musculoskeletal pathology. Further research is warranted to determine the potential effectiveness of Pilates for children and youth for various population groups and to develop comprehensive treatment guidelines.

Effect of Kinesio® Taping on Ankle Complex Motion and Stiffness and Jump Landing Time to Stabilization in Female Ballet Dancers

Ankle sprain is the most commonly diagnosed injury experienced by ballet dancers with few studies investigating preventive support measures such as Kinesio taping. The need exists to examine the mechanical support characteristics of Kinesio taping and effect of application on ankle motion and performance. This may be important to understanding the mechanical mechanisms attributed to Kinesio ankle taping and justify its use in the prevention and treatment of jump landing injuries in ballet dancers. This study compared Kinesio taping with and without tension and no tape (control) on active and passive measures of ankle complex motion in healthy ballet dancers. A secondary objective was to examine the effect of Kinesio taping on balance using time to stabilization. Participants performed three ballet jumps with single-leg landings on a force plate across three ankle support conditions consisting of Kinesio taping, sham-Kinesio taping, and no tape. Sagittal and frontal plane motion and load-displacement of the ankle complex for each support condition were obtained using an ankle arthrometer. Kinesio taping with tension significantly restricted inversion-eversion rotation and increased inversion stiffness of the ankle complex (p < 0.05). No significant differences were found among the three ankle support conditions for jump landing time to stabilization (p > 0.05). Arthrometric results indicate Kinesio taping significantly restricted ankle complex motion in the frontal plane that is associated with lateral ankle sprain. Objective information on the nature of Kinesio taping support can assist sports medicine practitioners when recommending ankle support to athletes.

Hypermobility of joints in dancers

OBJECTIVES

The current understanding of hypermobility and its diagnostic criteria is still insufficient to create a complete and systematic clinical presentation of the disorder. The objective of this study was to assess the prevalence of joint hypermobility syndrome (JHS) amongst a cohort of jazz dancers, by analyzing its presence in accordance with a number of diagnostic criteria, and to verify potential risk factors for joint hypermobility in jazz dancers.

METHODS

77 jazz dancers from the Polish Dance Theater were examined (58 female and 19 male). The prevalence of JHS was assessed using the following diagnostic tools: a structured interview, Beighton score, Grahame & Hakim questionnaire, and Sachse's criteria, in the modified version proposed by Kapandji.

RESULTS

The prevalence of JHS in this cohort of jazz dancers differed significantly, depending on which criteria were adopted (p = 0.001) with Beighton score, Grahame & Hakim questionnaire, and Sachse's criteria identifying 64.9%, 74% and 59.7% of the sample as JHS respectively. Hypermobility was significantly more prevalent in women than men (p < 0.05).

CONCLUSIONS

This study demonstrated a significant prevalence of joint hypermobility in jazz dancers and corroborates the findings of other researchers, indicating the need for unified diagnostic criteria for JHS in dancers.

Lower extremity biomechanics and muscle activity differ between 'new' and 'dead' pointe shoes in professional ballet dancers

The purpose of this study was to compare lower extremity (LE) biomechanics and muscle activity between 'new' and 'dead' pointe shoes in professional female ballet dancers performing relevé and arabesque. We compared sway area, peak ankle moments, and tibialis anterior and medial gastrocnemius muscle activation amplitudes. Nine ballet dancers participated (age = 22.2 ± 2.2 years, height = 163.2 ± 6.3 cm, body mass = 50.8 ± 6.5 kg) executed three trials of relevé and arabesque on pointe shoes under two conditions: 'dead' (108-144 training hours) and 'new' (3-36 training hours). While wearing 'dead' pointe shoes, dancers had significantly higher sway area during both relevé and arabesque (p = 0.017 and 0.028, respectively). Dancers exhibit significantly higher tibialis anterior activation (root mean square, %maximum voluntary contraction) during arabesque while wearing 'dead' pointe shoes (p = 0.043). No significant differences were identified in other dependent variables. The increased sway area and tibialis anterior muscle activity when wearing 'dead' pointe shoes during relevé and arabesque movements demonstrates that using 'dead' shoes is more demanding. Our findings provide quantitative evidence of possible deleterious biomechanical changes when wearing dead pointe shoes that may increase LE injury risk in dancers.

Screening Tools as a Predictor of Injury in Dance: Systematic Literature Review and Meta-analysis

BACKGROUND

Dance involves movements of complexity and physical intensity which result in stress on the body. As a consequence, dancers are at risk of injury which can impact on their well-being. Screening tools are used for injury prevention to identify those dancers at risk of injury. The aim of this study was to investigate which screening tools can predict injury in dancers, encompassing all dance genres, levels and ages.

METHODS

An electronic search of seven databases from their inception to December 2017 was conducted. The databases were the Allied and Complementary Medicine Database (AMED), CINAHL, eBOOK Collection (EBSCOhost), MEDLINE, Cochrane Database of Systematic Reviews, SPORTDiscus and PEDro: the Physiotherapy Evidence Base. The following search terms were used: (i) Dance AND injury AND Screening, (ii) Screening AND dance and (iii) Musculoskeletal AND Screening AND Dance. Studies were assessed using a 20-point scoring tool, and eligible studies were included in a meta-analysis.

RESULTS

The mean methodological quality score was 12.2 points. Injured dancers had a significantly higher compensated turnout range of motion than non-injured dancers: pooled mean difference of compensated turnout (23.29°; 95% CI 14.85-31.73; P < 0.00001; I² = 0%). Injured dancers had significantly greater functional turnout range of motion when compared to non-injured dancers: pooled mean difference of functional turnout (14.08°; 95% CI 7.09-21.07; P < 0.0001; I² = 0%). There also some evidence for use of hip range of motion as a predictor of dance injury.

CONCLUSIONS

Some evidence exists for the potential use of dance-specific positions as a predictor of injury. A number of studies were limited by a lack of prospective injury design, injury definition and self-reporting of injury.

Effect of expertise in ballet dance on static and functional balance

RESEARCH QUESTION

The purpose of this study was to examine the postural sway characteristics of the ballet dance experts in quiet standing and at their limits of stability with an approach not used before in dancers.

METHODS

The study was conducted on thirteen female ballet dancers and thirteen non-training females. The data were collected with a use of a force plate. To gain a better insight into the postural control processes, we used the rambling-trembling and sample entropy analyses in the COP data processing.

RESULTS

The main findings of the study showed professional dancers to have higher values of postural sway characteristics in comparison to the non-trainees while performing simple motor tasks. Also, higher values of the trembling component in the group of dancers during quiet standing and the inclined positions were observed. This might be a sign of higher capacity of the postural system to deal with postural instability in dancers.

IMPORTANCE

Our results confirmed that the visual information is important in the process of postural control of dancers', which is proven by increased dislocations of the COP without visual feedback. The sample entropy results indicated more irregular characteristics of postural sway in ballet dancers representing more automated postural control. The data analysis methods showed high sensitivity to the subtle changes in postural control due to the dance training.

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.

INJURIES IN PROFESSIONAL DANCERS: A SYSTEMATIC REVIEW

ABSTRACT Movement is a fundamental element of dance, and the dancer’s body is the raw material through which the art of dance is expressed; for this, it demands the utmost discipline in the pursuit of technical and artistic excellence. To meet the professional demands, dancers are subjected to strenuous training routines, which can lead to the development of injuries in this environment. The objective was to examine the etiology, main affected segments, prevalence, and instruments used to evaluate the lesions in studies with professional dancers and/or in comparison with similar populations. We selected articles published in the last decade in the databases BIREME, LILACS, MEDLINE EBSCO, WEB OF SCIENCE, SCOPUS (Elsevier), and PubMed, with cross-sectional, observational cohort and case control design published in Portuguese, English, or Spanish. Systematic reviews, case studies, dissertations, theses, book chapters, cross-referenced articles, and studies published outside of the last decade were not included. The search used combinations of the terms “dancing* and athletic injuries* and musculoskeletal* and pain*”. A principal investigator and two reviewers conducted the survey and analyzed all the potentially relevant articles, initially by the abstract and title. Twelve articles were included, with 1,149 participants (965 professional dancers of classical ballet, modern dance, contemporary dance, and breakdance, 104 amateur dancers, and 80 elite athletes). Nine studies found simultaneous lesions with emphasis on the foot and ankle (n=4), upper and lower limbs lesions (n=4) and lower and upper limb joints (n=1). Other studies have found lesions in the anterior cruciate ligament (n=3). There was no agreement regarding the instruments for detecting lesions in professional, pre-professional, and amateur dancers. There was a prevalence of studies aimed at classical ballet modality, evidencing a higher frequency of lower limb involvement in professional dancers.

Characteristics and prevalence of musculoskeletal injury in professional and non-professional ballet dancers

BACKGROUND:

Ballet is a high-performance activity that requires an advanced level of technical skills. Ballet places great stress on tendons, muscles, bones, and joints and may act directly as a trigger of injury by overuse.

OBJECTIVES:

1) to describe the main types of injuries and affected areas related to classical ballet and 2) to compare the frequency of musculoskeletal injuries among professional and non-professional ballet dancers, considering possible gender differences among the professional dancers.

METHOD:

A total of 110 questionnaires were answered by professional and non-professional dancers. The questionnaire contained items related to the presence of injury, the regions involved, and the mechanism of the injury.

RESULTS:

We observed a high frequency of musculoskeletal injuries, with ankle sprains accounting for 69.8% of injuries in professional dancers and 42.1% in non-professional dancers. Pirouettes were the most frequent mechanism of injury in professional dancers, accounting for 67.9% of injuries, whereas in the non-professional dancers, repetitive movement was the most common mechanism (28.1%). Ankle sprains occurred in 90% of the women's injuries, and muscle sprains occurred in 54.5% of the men's injuries. The most frequent injury location was the ankle joint in both sexes among the professional dancers, with 67.6% in women and 40.9% in men.

CONCLUSIONS:

The identification of the mechanism of injury and time of practice may contribute to better therapeutic action aimed at the proper function of the dancers' bodies and improved performance by these athletes.

Is There a Correlation Between Static and Dynamic Postural Balance Among Young Male and Female Dancers?

Aimed to investigate whether young male and female dancers have different patterns of association between static and dynamic postural balance (PB), 60 dancers from the Australian Ballet School (14-19 years old) were tested for static and dynamic PB with head and lumbar accelerometers. Monotonic relationships between static and dynamic PB were found in head movements among young female dancers in all three directions, but were found for young male dancers in the mediolateral (ML) and anteroposterior (AP) directions only. In lumbar movements, monotonic relationships were found for young female dancers in the AP direction only. Comparing head with lumbar movements in static PB, young male dancers demonstrated monotonic relationships between head and lumbar movements in all 3 directions; however, young female dancers demonstrated monotonic relationships in the AP direction only. In the dynamic measurements, both male and female dancers demonstrated monotonic relationships between head and lumbar movements for all parameters measured in the ML and vertical directions (p < .05). In conclusions, among female dancers static PB ability is correlated with their dynamic ability, whereas among male dancers, no relationship between the static and dynamic PB in the AP direction exists. Male dancers showed head and lumbar coordination in the static PB movement, but both genders manifested no head and lumbar coordination in the AP direction measured for dynamic PB.

The effect of textured ballet shoe insoles on ankle proprioception in dancers

BACKGROUND

Impaired ankle inversion movement discrimination (AIMD) can lead to ankle sprain injuries. The aim of this study was to explore whether wearing textured insoles improved AIMD compared with barefoot, ballet shoes and smooth insoles, among dancers.

METHODS

Forty-four adolescent male and female dancers, aged 13-19, from The Australian Ballet School were tested for AIMD while barefoot, wearing ballet shoes, smooth insoles, and textured insoles.

RESULTS

No interaction was found between the four different footwear conditions, the two genders, or the two levels of dancers in AIMD (p > .05). An interaction was found between the four different footwear conditions and the three tertiles when tested in ballet shoes (p = .006). Although significant differences were found between the upper tertiles and the lower tertiles when tested with ballet shoes, barefoot and with smooth insoles (p < .001; p < .001; p = .047, respectively), when testing with textured insoles dancers in the lower tertile obtained similar scores to those obtained by dancers in the upper tertile (p = .911).

CONCLUSION

Textured insoles improved the discrimination scores of dancers with low AIMD, suggesting that textured insoles may trigger the cutaneous receptors in the plantar surface, increasing the awareness of ankle positioning, which in turn might decrease the chance of ankle injury.

Effect of teaching with or without mirror on balance in young female ballet students

Background

In literature there is a general consensus that the use of the mirror improves proprioception. During rehabilitation the mirror is an important instrument to improve stability. In some sports, such as dancing, mirrors are widely used during training. The purpose of this study is to evaluate the effectiveness of the use of a mirror on balance in young dancers. Sixty-four young dancers (ranging from 9–10 years) were included in this study. Thirty-two attending lessons with a mirror (mirror- group) were compared to 32 young dancers that attended the same lessons without a mirror (non-mirror group). Balance was evaluated by BESS (Balance Error Scoring System), which consists of three stances (double limb, single limb, and tandem) on two surfaces (firm and foam). The errors were assessed at each stance and summed to create the two subtotal scores (firm and foam surface) and the final total score (BESS). The BESS was performed at recruitment (T0) and after 6 months of dance lessons (T1).

Results

The repeated measures ANOVA analysis showed that for the BESS total score there is a difference due to the time (F = 3.86; p < 0.05). No other differences due to the group or to the time of measurement were found (p > 0.05). The analysis of the multiple regression model showed the influence of the values at T0 for every BESS items and the dominance of limb for stability on an unstable surface standing on one or two legs.

Conclusions

These preliminary results suggest that the use of a mirror in a ballet classroom does not improve balance acquisition of the dancer. On the other hand, improvement found after 6 months confirms that at the age of the dancers studied motor skills and balance can easily be trained and improved.

Postural stability and ankle sprain history in athletes compared to uninjured controls

BACKGROUND

Diminished postural stability is a risk factor for ankle sprain occurrence and ankle sprains result in impaired postural stability. To date, ankle sprain history has not been taken into account as a determinant of postural stability, while it could possibly specify subgroups of interest.

METHODS

Postural stability was compared between 18 field hockey athletes who had recovered from an ankle sprain (mean (SD); 3.6 (1.5) months post-injury), and 16 uninjured controls. Force plate and kinematics parameters were calculated during single-leg standing: mean center of pressure speed, mean absolute horizontal ground reaction force, mean absolute ankle angular velocity, and mean absolute hip angular velocity. Additionally, cluster analysis was applied to the 'injured' participants, and the cluster with diminished postural stability was compared to the other participants with respect to ankle sprain history.

FINDINGS

MANCOVA showed no significant difference between groups in postural stability (P = 0.68). A self-reported history of an (partial) ankle ligament rupture was typically present in the cluster with diminished postural stability. Subsequently, a 'preceding rupture' was added as a factor in the MANCOVA, which showed a significant association between diminished postural stability and a 'preceding rupture' (P = 0.01), for all four individual parameters (P: 0.001-0.029; Cohen's d: 0.96-2.23).

INTERPRETATION

Diminished postural stability is not apparent in all previously injured athletes. However, our analysis suggests that an (mild) ankle sprain with a preceding severe ankle sprain is associated with impaired balance ability. Therefore, sensorimotor training may be emphasized in this particular group and caution is warranted in return to play decisions.

Equilíbrio estático e dinâmico em bailarinos: revisão da literatura

A dança envolve integração de movimento, equilíbrio postural e aspectos relacionados ao controle postural. Informações sobre o equilíbrio em bailarinos são de grande importância, pois eles são considerados modelos de controle postural. O objetivo foi revisar estudos sobre equilíbrio postural estático e dinâmico em bailarinos, caracterizando o controle e a dependência visual desses atletas para a manutenção do equilíbrio. Para isso, foi realizada uma revisão nas bases de dados PubMed, SciELO, Lilacs e Science Direct, considerando o período entre 1997 a 2013, utilizando os descritores equilíbrio, controle postural, plataforma de forças, ballet, bailarinos clássicos e aferência visual. Foram selecionados 18 artigos capazes de fornecer dados quantitativos para avaliação do equilíbrio nesses atletas classificados pelo nível de evidência científica Oxford. A literatura revisada mostra completa concordância quanto ao efeito da retirada da informação visual sobre a estabilidade postural de bailarinos considerados como executantes altamente treinados. Estudos mostrando a comparação do equilíbrio de bailarinos com outras técnicas desportivas confirmaram um padrão específico de equilíbrio nesses indivíduos. Entretanto, associando-se à restrição visual, bailarinos apresentaram maior deslocamento do centro de pressão comparado a outras modalidades desportivas, sugerindo maior dependência visual para a manutenção do equilíbrio. Bailarinos apresentam menor oscilação postural em relação a indivíduos não treinados e indivíduos treinados em outras práticas desportivas, com maior dependência visual para manutenção do equilíbrio.

Single leg balancing in ballet: effects of shoe conditions and poses

The purpose of this study was to describe the effects of lower limb positioning and shoe conditions on stability levels of selected single leg ballet poses performed in demi-pointe position. Fourteen female non-professional ballet dancers (mean age of 18.4±2.8 years and mean body mass index of 21.5±2.8kg/m(2)) who had practiced ballet for at least seven years, without any musculoskeletal impairment volunteered to participate in this study. A capacitive pressure platform allowed for the assessment of center of pressure variables related to the execution of three single leg ballet poses in demi pointé position: attitude devant, attitude derriére, and attitude a la second. Peak pressures, contact areas, COP oscillation areas, anterior-posterior and medio-lateral COP oscillations and velocities were compared between two shoe conditions (barefoot versus slippers) and among the different poses. Barefoot performances produced more stable poses with significantly higher plantar contact areas, smaller COP oscillation areas and smaller anterior-posterior COP oscillations. COP oscillation areas, anterior-posterior COP oscillations and medio-lateral COP velocities indicated that attitude a la second is the least challenging and attitude derriére the most challenging pose.

Changes in biomechanics and muscle activation in injured ballet dancers during a jump-land task with turnout (Sissonne Fermée)

Large impact loading with abnormal muscle activity and motion patterns may contribute to lower extremity injuries in ballet dancers. Yet, few studies investigated the influence of injury on the ballet movement. The purpose of this study was to find the neuromuscular and biomechanical characteristics in dancers with and without ankle injury during a jump-landing Sissonne Fermée task. Twenty-two ballet dancers were recruited and divided into the injured group (n = 11) and the uninjured group (n = 11). They performed a ballet movement called "Sissonne Fermée" with reflective markers and electrodes attached to their lower extremities. Ground reaction force, joint kinematics, and muscle activity were measured. The injured dancers had greater peak ankle eversion but smaller hindfoot-to-tibial eversion angles. Also, the injured dancers had greater activity of the hamstring of the dominant leg and tibialis anterior of the non-dominant leg during the pre-landing phase. The injured dancers had greater tibialis anterior activity of the dominant leg but less muscle activity in the medial gastrocnemius of the non-dominant leg during the post-landing phase. The injured dancers had a greater co-contraction index in the non-dominant ankle and a lower loading rate. The higher co-contraction indices showed that the injured dancers required more muscle effort to control ankle stability. Furthermore, the injured dancers used a "load avoidance strategy" to protect themselves from re-injury. Neuromuscular control training of the ankle joint for ballet dancers to prevent injury is necessary.