Prevalence and risk factors of musculoskeletal injuries in modern and contemporary dancers: a systematic review and meta-analysis.

Background: A large number of studies have found that the musculoskeletal injury of modern and contemporary dancers has a high incidence. Previous publications have indicated that there are many potential factors that are related to dancing injury; however, they have not been proven, and even some data are conflicting in different research. Results: The search yielded 18 prospective studies reporting on professional and pre-professional modern or contemporary dancers from companies and schools. The prevalence of modern and contemporary dancers was 0.82 (95% CI: 0.74~0.90). The injury proportion of trauma, overuse, ankle and foot, lower extremity, joint and ligaments, muscle and tendons, and time-loss were 0.40, 0.26, 0.49, 0.34, 0.33, and 0.29 in the total number of injuries. There was no evidence of a significant difference in sex, age, and education program. The factors of BMI and injury history achieved statistical significance, and the p-values were less than 0.01. Conclusion: Based on the results of this article, BMI and injury history may be risk factors for injury in contemporary and modern dancers. Modern and contemporary dancers have a high prevalence of musculoskeletal injuries. Lower extremity injuries are the most common in the whole body, with injuries to the foot and ankle being more frequent. The mechanism of injury is mostly overuse injury, and the injured tissues are mostly muscle tendons and joint ligaments.

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.

Balletic bodies under lockdown: The consequences of a pandemic for highly disciplined habitus.

Like other elite athletes, ballet dancers are highly dedicated to the pursuit of their vocation. They work to perfect their bodies, their movements and their expression of the art form. The lockdowns that occurred during the COVID-19 pandemic represented a significant interruption to the extraordinary but everyday lives of ballet dancers, creating unique environments where exploration of the embodied habitus of ballet can be further investigated. The impacts of lockdown upon dancers were explored via a series of interviews with 12 professional dancers from Germany. Framed by previous research, theorising the balletic body from a Bourdieusian perspective, interview data were analysed using Interpretative Phenomenological Analysis. Our research highlights the way in which COVID-19 lockdowns and associated restrictions disrupt the habitus of dancers and results in a form of suffering that is comparable to injury or chronic illness. Our research suggests that individuals respond to the 'structural injuries' of lockdown measures in a manner comparable to the way they respond to physiological injury. Thus, dancers sought to repair or re-establish the social structures they ordinarily inhabit whilst the inevitable limitations of such efforts engendered occasions for reflexive thinking about their role, careers and identity as dancers.

Plantar intrinsic foot muscle activity and its relationship with postural sway during tiptoe standing in ballet dancers and non-dancers.

BACKGROUND: Minimizing postural sway during tiptoe standing is essential for ballet dancers. Investigation of the activity of the plantar intrinsic foot muscles (PIFMs) may provide insight into postural sway in dancers. Herein, we compared PIFM activity during tiptoe standing between dancers and non-dancers and examined its relationship with postural sway. METHODS: We enrolled 14 female ballet dancers and 13 female non-dancers. Electromyography (EMG) amplitudes of 64 channels of PIFMs and center of pressure (COP) data were recorded during bipedal tiptoe standing tasks performed with ankle plantarflexion angles of 20°, 40°, and 60° (dancers only). The EMG amplitudes were normalized to those during the maximum voluntary contraction, and the muscle activity level and its coefficient of variation over time (EMG-CVtime) during the task were assessed. Standard deviations in the anteroposterior and mediolateral directions, velocity, and area were calculated from the COP data. RESULTS: Most COP and EMG variables were significantly lower in dancers than in non-dancers in both the 20° and 40° tasks (p < 0.05). Significant correlations were found between most combinations of the COP and EMG variables in both the 20° and 40° tasks in the whole cohort (r = 0.468-0.807, p ≤ 0.014). In the 60° task in dancers, COP velocity was strongly correlated with EMG-CVtime (r = 0.700, p = 0.005). CONCLUSION: These results provide novel evidence that the PIFMs do not require high activity, but rather that its low, steady activity is the key, to achieve less postural sway during bipedal tiptoe standing in dancers.

Jumping demands during classical ballet class.

Ballet class represents a considerable portion of professional ballet training, yet the external training load demands associated with class-and particularly the jumping demands-have not been investigated. The purpose of this study was to measure the jumping demands of ballet class by sex and rank. Eleven female and eight male elite professional ballet dancers participated in 109 ballet classes taught by 12 different teachers. Jump counts and jump heights were measured during each class. A Poisson generalized linear mixed effects model was used to examine the differences in jump counts between sexes and ranks. Greater jump counts were observed during class in men than in women (153, 95% confidence intervals [CI] [137, 170] vs. 119, 95% CI [109, 131], p = 0.004) and in junior ranking dancers compared with senior ranking dancers (151, 95% CI [138, 165] vs. 121, 95% CI [108, 135], p = 0.006). Female junior and senior ranking dancers jumped at rates of 9.2 ± 2.6 and 8.6 ± 4.7 jumps·min-1 , respectively, while male junior and senior ranking dancers jumped at rates of 9.1 ± 2.6 and 8.7 ± 2.6 jumps·min-1 , respectively. Across all classes, 73% of jumps observed were below 50% of maximum double-legged countermovement jump height. Unlike rehearsals and performances, class offers dancers an opportunity to self-regulate load, and as such, are a useful session to manage jump load, and facilitate gradual return-to-dance pathways. Communication between health care and artistic staff is essential to facilitate load management during class.

Dynamic Gait Stability and Spatiotemporal Gait Parameters During Overground Walking in Professional Ballet Dancers.

Introduction: It has been recognized that practicing ballet could strengthen the leg muscles, improve balance, and reduce fall risk. However, few studies have investigated how ballet practice alters a person's gait pattern, and this knowledge gap could present a barrier to designing ballet-based training programs. This study examined dynamic gait stability and spatiotemporal gait parameters among professional ballet dancers during normal level overground walking. Methods: Twenty young adults were recruited: 10 ballet dancers (24.5 ± 4.9 years) and 10 age- and sex-matched non-dancers (22.6 ± 3.4 years). Participants walked on a 10 m linear walkway at their self-selected speed. Dynamic gait stability and common gait parameters (step length, step width, gait speed, and cadence) were determined from the collected kinematic data and compared between groups with a significance level of .05. Results: The results showed that both groups displayed comparable dynamic gait stability at touchdown (P = .140) and liftoff (P = .638). However, ballet dancers walked with a longer (P = .054), narrower (P = .009), and faster step (P = .014) at a marginally quicker speed (P = .063) than non-dancers. Conclusion: Our study suggests that young professional ballet dancers have different gait patterns, but similar dynamic gait stability compared to non-dancers. These findings not only provide insight into the mechanisms of dynamic stability control among young ballet dancers during gait but expand our understanding of the control of dynamic gait balance of human locomotion across a wide variety of populations and walking conditions.

Strength Training Perceptions Amongst Vocational Circus and Dance Students.

Introduction: The aim of this study was to analyze perceptions of strength training in vocational circus and dance students. It was hypothesized that due to the higher relative strength demands and associated risks of working at height in some aerial and acrobatic disciplines that circus students would be more open to strength training than dancers. Methods: Eighty students completed the Training Information Survey (TIS) (Mean age = 20.74 ± 2.71); 39 circus students and 41 dance students. 97% of circus students and 69% of dance participants reported that strength training was a required part of their training with students participating in strength training 4.24 ± 0.98 and 3.05 ± 1.42 day per week respectively. Results: Perceptions of strength training amongst vocational circus and dance students appear to be favorable, with both sets of students strongly agreeing with the statements "Strength training is essential to my overall development as a dancer/circus artist" (5.00 (IQR 1.00) and 5.00 (IQR 1.00) respectively). Following Bonferonni correction only one statement returned statistically significant results with dance students agreeing more strongly with the statement "Strength training increases muscle size," U = 473.00, P = .001. Students also agreed that strength training helped them to feel better mentally and physically, that strength training is beneficial for both men and women and that it should not be designated as specific to either sex. Conclusion: Results support earlier studies that suggest a cultural shift in perceptions of strength training and ideal esthetic in dance, particularly amongst students and that they are keen to incorporate strength training into their practice. Educational establishments should note students' interest in participating in strength training, reviewing how to embed effective strength training education, more coaching and time allowance for these activities within their timetable. Further research with a greater sample size is recommended to further substantiate these indications of a shift in perceptions.

Different Types of Training Lead to Different Levels of Cardiovascular Energy Dissipation: Young Soccer Players Versus Ballet Dancers.

INTRODUCTION: Arterial wall viscosity is a source of energy dissipation that takes place during mechanical transduction. In our previous studies, a "global" damping effect in endurance training athletes was introduced, verifying that endurance-athletes dissipate greater pulsatile energy in the circulation compared with healthy untrained subjects. OBJECTIVE: To investigate the wall energy dissipation in the vascular bed for each beat and within the conceptual framework of ventricular-arterial coupling, in order to elucidate if different types of training could lead to differentiated levels of cardiovascular energy dissipation. MATERIALS AND METHODS: Data from subjects with different kinds of training (soccer players and ballet dancers) have been collected noninvasively and compared with a control group of untrained individuals to analyse the differentiating characteristics of the subjects, especially in terms of Stroke Work Dissipation (WDIS). RESULTS: In the endurance-trained individuals, an enhanced WDIS has been observed compared to the untrained individuals (p<0.05). However, non-significant differences were found regarding ballet-dancers group. CONCLUSION: Changes in wall energy dissipation are developed under high intensity endurance training routines.

Kinematic Motor Synergy Analysis to Understand Lock Dance Choreographies.

Lock dance, or locking, is one of the popular old-school street dance styles featuring sharp, sudden, and isolated body movements through intricate control and coordination of joints and muscles. This work aims to understand the complex lock dance motions based on kinematic motor synergy analysis. Lock dance motions performed by three experienced dancers were measured with a markerless human motion capture technique. The motor synergies were identified and summarized using principle component analysis (PCA). The motion complexity, joint contributions, and motor coordination of ten basic lock dance choreographies were analyzed based on the synergy patterns and their activations. The results enhance our understanding of complex dance motions and serve as a step toward future applications to, e.g. dance skill or injury risk assessments.

Dermatologic conditions in dancers: a statewide survey.

Performing artists, such as dancers, singers, actors and musicians, rely on their physical bodies to successfully execute their artforms. However, literature regarding dermatologic conditions that impact dancers is lacking. An anonymous REDCap® secure survey was distributed by email to Dance Majors, Dance Minors, and Dance Instructors/Professors at five Virginia undergraduate institutions. Responses regarding demographics, style of dance, and dermatological diseases were recorded over a 2 month period. When asked about developing skin disease, 57 (59%) of survey participants reported experiencing skin diseases, such as acne, eczema, hyperhidrosis, and plantar warts. When asked about skin diseases exacerbated or believed to be caused from dancing, 56 (59%) reported blisters, callouses, skin splitting, nail/foot infection, ingrown nails, and floor burns. This study demonstrates two main findings: dancing may exacerbate current skin disorders and some skin conditions may be caused by dancing. Additionally, the common practice of dancing barefoot likely contributes to the development of certain skin conditions. Limitations include sample size, response bias, and lack of validation of the survey.

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.

The interactions between agonist-to-antagonist muscle strength performance and plantar pressure distribution, foot contact area, and impulse in novice ballet dancers.

BACKGROUND: Hip, trunk, knee, and ankle/foot muscles may lead to increased variability in the components of balance and plantar pressure distribution (PPD) analysis. However, the role of these muscle groups in the PPD of different ballet techniques in novice ballet dancers has not previously been studied. OBJECTIVE: Our objective was to examine whether balance and PPD vary among five different ballet techniques and correlate with the agonist-to-antagonist strength performance of trunk, knee, hip, and ankle muscles in adolescent ballet dancers. METHODS: The anthropometric parameters, muscle strength performance, balance, and PPD of sixty healthy female ballet dancers (age: 14.36 ± 2.18 y) were measured at 48-h intervals. RESULTS: The forefoot's PPD was significantly greater than the midfoot and rearfoot for all techniques (p= 0.000). The percent plantar load of forefoot during développé à la seconde (side, front, back), passé, and penché was greater than midfoot (166.56%, 161.51%, 168.11%, 165.14%, 174.04%) and rearfoot (47.75%, 32.84%, 43.83%, 48.73%, 49.66) for all techniques, respectively. The forefoot's PPD, impulse, and contact area during all techniques were significantly correlated with the trunk muscle strength ratio (p< 0.05). CONCLUSION: Ballet dancers with higher trunk muscle strength imbalance showed a greater percentage difference in pressure load between the left and right foot in the anterior and posterior directions, poor balance, aggravated trunk imbalance, increased PPD, contact area, and impulse in the forefoot during each technique.

Low Stiffness Dance Flooring Increases Peak Ankle Plantar Flexor Muscle Activation During a Ballet Jump.

INTRODUCTION: Research in court sports shows that factors which aid in extrinsic shock absorption, that is, flooring and footwear, can help reduce lower extremity injuries. However, since students and performers of ballet or most styles of contemporary dance cannot depend upon footwear, the only extrinsic factor to help them with shock absorption is flooring. METHODS: We investigated whether doing sauté on a low stiffness dance floor produced a difference in EMG output of the vastus lateralis, gastrocnemius, of soleus compared to a high stiffness floor. Average and average peak amplitude EMG output from 18 dance students or active dancers performing 8 repetitions of sauté on a low stiffness floor (Harlequin® Woodspring) was compared to a maple hardwood floor on concreted subflooring. RESULTS: The data showed a significant increase in average peak EMG muscle amplitude during jumping on the low stiffness floor compared to a high stiffness floor for the soleus muscle (P = .033) and a trend for increase average peak output for the medial gastrocnemius (P = .088). CONCLUSION: The difference in average peak amplitude of EMG output is explained through the difference in force absorption between floors. With the high stiffness floor, more force of the landing was returned to the dancers' legs, but the low stiffness floor absorbed some of the force of landing the jump, and therefore muscles needed to contribute more to maintain the same jump height. The force absorption characteristic of the low stiffness floor may decrease injury rates in dance through causing an adjustment in muscle velocity. Rapid eccentric muscle activity carries the greatest possibility of musculotendinous injury and is experienced in lower body muscles controlling all joints during impact absorption, which includes landing of jumps in dance. If a surface can decelerate the landing of a high velocity dance movement, it also decreases the musculotendinous demand for high velocity tension generation.

Dance as a neurorehabilitation strategy: A systematic review.

OBJECTIVE: This systematic review aimed to demonstrate the benefits of dance-based therapeutic interventions in rehabilitation processes in patients with neurological disorders. METHODS: Searches on the following databases and electronic search engines were conducted: MEDLINE, LILACS, Science Direct, SCOPUS, PeDro, BVS (virtual health library), and Google Scholar. Data extraction was independently performed by two authors. Twenty-five clinical trial-type studies that included dance and established outcome measures were included, and studies in which a musicalized exercise modality was used without the connotation of dance were excluded. RESULTS: From the results of multiple studies, the short-term motor benefits of rhythmic auditory stimulation on gait parameters were highlighted. Furthermore, there was scientific evidence demonstrating the benefits of the cognitive and social parameters of group dancing as significant improvements in cognitive flexibility and processing speed were highlighted. Recent studies showed that interventions based on exercise and/or rhythmic choreography can reduce the risk of falls in patients with neurological disorders, thereby improving their quality of life. CONCLUSION: These findings suggest that dance is an innovative and effective method that can be included in therapies as it allows for a promising prognosis in motor, cognitive, and social performances of patients with neurological disorders that alter mobility and quality of life.

Differences in Center of Pressure Displacement and Lower Limb Muscle Activity During Relevé Descending Phase Comparing Flat Shoes and Pointe Shoes.

AIMS: In classical ballet, dancers may wear flat shoes and pointe shoes. To consider the kinematic changes between flat shoes and pointe shoes to prevent injuries, it is essential to focus on the fundamental ballet movement of standing on pointe. This study aimed to clarify the differences in the center of pressure (COP) displacement and lower limb muscle activity during the descending phase of a relevé when wearing pointe shoes versus flat shoes. METHODS: Ten amateur ballet dancers volunteered for this study and performed a reléve wearing flat shoes and pointe shoes. We measured the COP displacement by using a footplate and electromyographies of the tibialis anterior, soleus, lateral gastrocnemius, and peroneus longus muscles during the relevé descending phase. These data were compared using a paired t-test or Wilcoxon signed-rank sum test. RESULTS: The COP significantly shifted to the lateral side when dancers were wearing pointe shoes compared to wearing flat shoes (p<0.05). The muscle activity of the tibialis anterior and soleus muscles was significantly higher by 5.7% and 5.3%, respectively, when ballet dancers were wearing pointe shoes compared to flat shoes (p<0.05). However, there were no differences in both lateral gastrocnemius and peroneus longus. CONCLUSION: Greater muscle activities in the tibialis anterior and soleus muscles when wearing pointe shoes than when wearing flat shoes were associated with a larger lateral displacement of the COP. To control the COP displacement during the descending phase of a relevé, the muscle activity of the peroneus longus, which is antagonist of tibialis anterior muscle, and soleus muscles should be increased.

Validity and Reliability of the Pre-Adolescent Dance Injury and Participation Questionnaire (PADIP-Q).

INTRODUCTION: Dancers generally begin training in a variety of styles at a young age. Across ages and levels of participation, dancers are at high risk for injury. Most available injury surveillance tools, however, have been developed for adult populations. Valid, reliable tools that monitor injury and exposure of pre-adolescent dance populations are limited. Therefore, the purpose of this study was to determine the validity and reliability of a dance injury and participation questionnaire specifically for pre-adolescent private studio dancers. METHODS: Four stages of validity and reliability testing assessed a novel questionnaire: initial design based on previous literature, expert panel review, cognitive interviews, and test-retest reliability. The target population was 8 to 12-year-olds who participate in at least 1 class/week at a private studio. Feedback from a panel review and cognitive interviews was incorporated. Test-retest analyses included Cohen's kappa coefficients and percent agreement for categorical variables, and intraclass correlation coefficients [ICCs (3,1)], absolute mean difference (md) and Pearson's correlation coefficients (r) for numerical data. RESULTS: The final questionnaire was comprised of 4 sections: demographics, dance training history, current dance participation (previous 1-year and 4-months), and dance-related injury history (previous 1-year and 4-months). Items with categorical responses estimated kappa coefficients from 0.32 to 1.00, and percent agreement between 81% and 100%. For items with numeric responses, ICC estimates ranged between .14 and 1.00, r values between .14 and 1.00, and the largest absolute md was 0.46. The 4-month recall sections revealed higher agreement than the 1-year sections. CONCLUSION: This valid pre-adolescent dance injury and participation questionnaire demonstrates good to excellent reliability across all items. To support participant completions, assistance from a parent/guardian is suggested. To move dance epidemiology research forward among private studio dancers aged 8 to 12 years, employment of this questionnaire is therefore recommended.

Spinal Counts, Impact, and Partnering Movements in Ballet, Modern, and Hip Hop dance: A YouTube Video Analysis Study.

INTRODUCTION: Dancers have self-reported a link between spinal extension movements and low back pain (LBP). Researchers have not reported the total number or frequency that spinal movements occur in ballet, modern, or hip-hop dance classes or performances. The purpose of this study was to report the number of spinal movements dancers are exposed to in different dance environments. MATERIALS AND METHODS: We analyzed 65 dance videos on YouTube.com for dance movements within 7 dance environments: ballet class and performance, modern class and performance, and hip-hop breaking, ciphers (large groups), and battles ("1v1s"). Two reviewers recorded counts of spinal (spinal flexion, extension, lateral flexion, and rotation), impact (jumps, leaps, and falls), and partnering movements (lifts, catches, and leans). Data analyses were processed in Jamovi (the jamovi project, Sydney, Australia). We reported movement totals, percentages, frequency, ranges, means with standard deviations (SD), and medians with interquartile range (IQR). We calculated significant differences using Mann-Whitney U tests. RESULTS: Video length ranged from 3 to 141 minutes (mean ± SD: 38.4 ± 38.3, range: 138). the average spinal extension movements ranged from 2 ± 0.8 to 7 ± 9.6 movements per minute across genres. Modern dance class had the most spinal flexion (89 ± 53.6), rotation (60 ± 40.8), and lateral flexion (74 ± 20.7) movements. Ballet performance had the most spinal extension movements (77 ± 69.8), jumps (74 ± 48), and leaps (19 ± 18.2). Hip-hop breaking had the highest number of falling movements (2 ± 2.3). Partnering movements were only present in ballet performance, modern dance performance, and hip-hop breaking environments. CONCLUSIONS: Movements that increase LBP occur often in all 3 dance genres. Dancers can expect frequent exposure to spinal extension movements; therefore, we recommend strengthening back and core musculature for all dancers. We recommend that ballet dancers also strengthen their lower extremity muscles. For modern dancers, we recommend strengthening their obliques. For hip-hop dancers, we recommend increasing muscular power and muscular endurance.

Adolescent Dance Team Fitness: Initial Quantitative Normative Values.

BACKGROUND: Research on improving dancer fitness to enhance performance capacity and prevent injury continues to grow. Fitness research for the adolescent dance team population, however, presents an evidence void. PURPOSE: Utilizing studio-based assessments, this descriptive quantitative study reveals an initial set of fitness normative values for the female adolescent competitive dance team dancer population. METHODS: 115 female dance team dancers ages 12 to 17 participated in a 90-minute field test assessment battery for cardiorespiratory fitness, muscle endurance of the upper body, lower body, and core, and lower extremity power. Descriptive statistics (mean, standard deviation, and interquartile range) created an initial set of quantitative fitness normative values for this population. RESULTS: Dancers' results revealed 29.5mL/O2×min ± 5.7 estimated VO2max, 35 ± 16 push ups, 62 ± 14 half sit ups, 51 ± 13 squats in 1 minute, 190 ± 23 cm broad jump, 445 ± 65 cm right lower extremity triple hop, and 450 ± 69 cm/left lower extremity triple hop. CONCLUSION: Discussion includes comparison of findings relative to previously established adolescent fitness and dancer normative data. Discussion also suggests implications, study limitations, and future research directions.

Analysis of Serum Ferritin Levels in a Group of Elite Ballet Dancers.

INTRODUCTION: Iron plays a significant role in energy production. However, it is not uncommon for athletes to be diagnosed with iron deficiency (ID), suggesting a correlation between performance and iron regulation. As a result, the International Olympic Committee has recommended iron screenings during health evaluations for elite athletes. Furthermore, athletes participating in esthetic sports are at increased risk for suboptimal iron intake due to disordered eating. Therefore, the purpose of this study was to investigate the distribution of serum ferritin (SF) in a cohort of elite ballet dancers and determine associations between vitamin D, anthropometric measures, stress injury, and dietary preferences. METHODS: Electronic health records of 40 elite ballet dancers (22 female, 18 male), age 19 to 38 years old, from the 2020 to 2021 pre-participation physical screening were examined. Chi squared comparisons were calculated to evaluate the association between SF and additional variables (ie, gender, age, height, weight, body mass index, vitamin D, stress injury history, and dietary preferences). SF values were compared to published normal and athletic population data. RESULTS: 58.97% of participants displayed normal or above SF values (>50 ng/ml), while 41.02% displayed minimal (<50 ng/ml) to depleted (<0.12/ng/ml) SF values. Approximately, 68% of the female dancers were ID and did not meet the minimal value needed for athletes. Females were more likely to have lower SF distributions (x2 [4] = 15.6377, P = .004) compared to male dancers. Additionally, dancers who reported dietary preferences (ie, vegetarian) were more likely to display lower SF distributions (x2[4] = 13.3366, P = .010). CONCLUSION: Over half of the female elite ballet dancers were ID which is consistent with current research. Females were at a significant higher risk compared to male dancers who reported dietary preferences. These findings suggest iron screenings should be considered in elite dancer populations.

Hip Hop Party Dance: Cardiorespiratory Profile and Responses to a Predefined Sequence.

Hip hop is a popular dance genre practiced worldwide that has gained popularity since the 1970s. Despite this, studies related to the area and its physiological demands are still scarce. The purpose of this study was to report the cardiorespiratory profile of a group of male and female hip hop dancers to determine the zones of intensity of a predefined hip hop party dance sequence. Eight Brazilian professional hip hop dancers, four women and four men, mean age 22 ± 2.3 years, participated in the study. Using a portable gas analyser (Cosmed K5) their cardiorespiratory variables were measured at two different times: first, during a maximal treadmill test and later during a predefined hip hop party dance sequence. Descriptive statistics (mean and standard deviation) were used for calculating the dependent variables: oxygen consumption (VO2), heart rate (HR), and the intensity zones for the predefined hip hop sequence. Data normality was verified using the Shapiro-Wilk test. The Mann-Whitney U-test was performed to check any sex-related difference (p < 0.01). No statistical difference between male and female dancers was found in the cardiorespiratory profile and responses to the predefined hip hop party dance sequence. On the treadmill, the participants' VO2peak was 57.3 ± 12.7 ml·kg-1·min-1, and HRmax was 190.0 ± 9.1 b·min-1. The predefined hip hop party dance sequence was mainly (61%) performed in the moderate aerobic zone. However, when the dancers jumped, the intensity of the sequence increased. This information could be used to develop a specific supplementary training protocols for hip hop dancers to improve their physiological fitness parameters and reduce the incidence of injury.