• A Bibliographic Review of Medicine and Science Research in DanceSport

      Wyon, Matthew; Riding-McCabe, T; Ambegaonkar, J; Redding, E (Science & Medicine, 2013-06)
      DanceSport is the competitive form of ballroom dancing, and even though it has more participants worldwide than ballet and modern dance, there is less peer-reviewed research. A review was conducted to identify all relevant literature to help researchers and clinicians gain an enhanced understanding of dancesport. Eight databases were searched, with 34 articles found in topics including participation motives, psychology, exercise physiology, fitness training, injuries and injury prevention, biomechanics, menstrual dysfunction, and substance use. Our results indicate that researchers have been inconsistently recording and reporting anthropometric and dancesport data; for example, 31 studies separated participants by gender, 21 included the competition classification of dancers, 19 reported which style of dancesport participants competed in, and 13 described the participants as a dance couple. Common injuries affected the neck, shoulder, spine, knee, lower leg, and foot. Dancesport is in the very heavy to extremely heavy category in energy expenditure (mean heart rate: male 175.2 ± 10.7, female 178.6 ± 8.6 bpm) and utilizes both aerobic and anaerobic energy systems. Alpha-beta and heart rate variability intervention techniques are reported to successfully enhance performance in dancers. Dancesport participants also appear less likely to smoke cigarettes, but have little knowledge about anti-doping rules. During events, professionals danced farther (30 m) and faster (0.3 m/sec) than junior dancers. Female competitors were more likely to be eumenorrheic. Dancesport is a physically and mentally demanding competitive sport, but there is a need to standardize measurements in future studies to allow comparison.
    • An international study on dietary supplementation use in dancers.

      Brown, Derrick; Wyon, Matthew (Science & Medicine, 2014-12)
      Little is known of the prevalence and motives of dietary supplement use amongst dancers from different cultures. Investigating supplement use, presumed effects, and other factors may be crucial for improving educational and nutritional advice provided for this cohort. Therefore, this study investigated the use of dietary supplements in 334 dancers from 53 countries, who completed a digitally based 35-question survey detailing demographic information and the use of dietary supplementation. Supplement use was prevalent amongst this international cohort, with 48% reporting regular supplement use. Major motives for supplement use were to improve health, boost immunity, and reduce fatigue. Forty-five percent believed that dancing increased the need for supplementation, whilst 30% recognized that there were risks associated with nutritional supplementation. The most frequently consumed supplements were vitamin C (60%), multivitamins (67%), and caffeine (72%). A smaller group of participants declared the use of whey protein (21%) or creatine (14%). Supplements were mainly obtained from pharmacies, supermarkets, and health-food stores. Dancers recognized their lack of knowledge in dietary supplement use and relied on peer recommendations instead of sound evidence-based advice from acknowledged nutrition or health care professionals. This study demonstrates that dietary supplement use is internationally prevalent amongst dancers. Continued efforts are warranted with regard to information dissemination.
    • Anthropometric factors affecting vertical jump height in ballet dancers

      Wyon, Matthew A.; Allen, Nicolas; Angioi, Manuela; Nevill, Alan M.; Twitchett, Emily (International Association for Dance Medicine and Science, 2006)
      Jumping plays an integral part of ballet performance and this study examines some of the ballet dancer’s characteristics that influence jump height. Forty-nine dancers (M = 21; F = 28) completed a series of tests that included two footed vertical jump height, single leg vertical jump height and anthropometric measurements. Supplemental training history and company position were also recorded. Statistical analysis (ANCOVA and MANOVA) indicated males had a greater vertical jump height than females (p < 0.01) and soloist and first artists had significantly greater vertical jump height than principals and artists for both male and females (p < 0.05). Anthropometric data indicated males having significantly larger leg girths than females. Males and females had no significant bilateral differences in girth measurements though male artists had significantly smaller thighs and calves than the other seniority levels (p < 0.05). Supplemental training did not influence jump height in this study’s population though males carried out significantly more weight training (p < 0.01) and females more aerobic training (p < 0.05). When jump height was analyzed in relation to cross-sectional area of the calf and thigh, there was no gender difference (p > 0.05). These results corroborate to previous research and also provide greater insight on how anthropometric and choreographic factors potentially influence vertical jump height in ballet dancers. The ineffective influence of supplemental training on vertical jump height needs greater examination. How other training regimens could influence jump height in dancers needs to be examined.
    • Anthropometry, somatotypes, and aerobic power in ballet, contemporary dance, and dancesport.

      Liiv, Helena; Wyon, Matthew A; Jürimäe, Toivo; Saar, Meeli; Mäestu, Jarek; Jürimäe, Jaak (Science & Medicine, 2013-12)
      This study compared anthropometric variables, somatotypes, and aerobic capacity between three groups of dancers: classical ballet dancers (M 33, F 56), contemporary dancers (M 28, F 109), and dancesport dancers (M 30, F 30). The assumption was that different functional requirements should produce differences in the anthropometric and aerobic capacity variables among the three groups. Anthropometric data for body mass index (BMI) and somatotypes were measured. Body fat percentage was measured by dual-energy x-ray absorptiometry. Maximal oxygen consumption and aerobic power were measured during an incremental treadmill test until exhaustion. Dancesport athletes were taller compared with same gender contemporary dancers (p<0.05). Female ballet dancers had a lower body mass and BMI compared with their contemporary dance and dancesport equivalents (p<0.001). There was significant difference between dance styles in endomorphy (F2,221 = 8.773, p<0.001) and mesomorphy (F2,221 = 21.458, p<0.001) scores. Dancesport dancers had significantly greater VO2max values (p<0.01). It was concluded that female contemporary dancers are generally more muscular than their ballet counterparts, while dancesport dancers are taller and heavier, less muscular, with slightly greater adioposity compared to the classical ballet dancers. Ballet dancers had the lowest body fat percentage, weight, and BMI values. Dancesport dancers had greater aerobic capacity than the ballet dancers. Based on this study, we conclude that dancers in these three styles differ in some aspects of anthropometric variables, somatotypes, and aerobic capacity, but we cannot say is it because of the training or selection or both.
    • Assessment of maximum aerobic capacity and anaerobic threshold of elite ballet dancers

      Wyon, Matthew; Allen, N; Cloak, R; Beck, S; Davies, P; Clarke, F (Science & Medicine, 2016-01)
      An athlete’s cardiorespiratory profile, maximal aerobic capacity and anaerobic threshold, is affected by their training regimen and competition demands. The purpose of the present study is to ascertain whether there are company rank differences in maximal aerobic capacity and anaerobic threshold in elite classical ballet dancers. Seventy-four volunteers (M=34, F=40) were recruited from two full-time professional classical ballet companies. All participants completed a continuous incremental treadmill protocol with a 1 km.h-1 speed increase at the end of each 1-minute stage until termination criteria had been achieved (e.g. voluntary cessation, RER <1.15, heart rate ±5b.min-1 of estimated HRmax). Peak VO2 (5-breathe smooth) was recorded and anaerobic threshold calculated using ventilatory curve and ventilatory equivalents methods. Statistical analysis reported between-subject effects for gender (F1,67=35.18; p<0.001) and rank (F1,67=8.67; p<0.001); post hoc tests reported soloists (39.5 ±5.15 ml.kg-1.min-1) as having significantly lower VO2 peak than artists (45.9 ±5.75 ml.kg-1.min-1, p<0.001) and principal dancers (48.07 ±3.24 ml.kg-1.min-1, p<0.001). Significant differences in anaerobic threshold were reported for age (F1,67=7.68; p=0.008), rank (F1,67=3.56; p=0.034); post hoc tests reported artists (75.8 ±5.45%) having significantly lower %AT than soloists (80.9 ±5.71, p<0.01) and principals (84.1 ±4.84%, p<0.001). The observed differences in VO2 peak and anaerobic threshold between the ranks in ballet companies is probably due to their different rehearsal and performance demands.
    • Ballet injuries: injury incidence and severity over 1 year.

      Allen, Nick; Nevill, Alan; Brooks, John; Koutedakis, Yiannis; Wyon, Matthew (Lippincott, Williams & Wilkin, 2012-09)
      STUDY DESIGN: Prospective, descriptive single-cohort study. OBJECTIVE: To assess the incidence and severity of injuries to a professional ballet company over 1 year. METHODS: Data for an elite-level ballet company of 52 professional dancers were collected by an in-house medical team using a time-loss injury definition. RESULTS: A total of 355 injuries were recorded, with an overall injury incidence of 4.4 injuries per 1000 hours (female, 4.1; male, 4.8; P>.05) and a mean of 6.8 injuries per dancer (female, 6.3; male, 7.3; P>.05). Mean injury severity was 7 days (female, 4; male, 9; P<.05). Most injuries were classified as overuse (64%; female, 68%; male, 60%; P>.05); mean severity of injury was 3 days for females and 9 days for males (P<.05). The percentage of traumatic injuries was 32% for females and 40% for males (P<.05); the corresponding severity was 6 and 10 days, respectively (P<.05). CONCLUSION: The relatively high number of injuries reported and the resulting loss of dance time support the need to introduce interventions to reduce the risk of injury in professional dancers.
    • Bilateral differences in peak force, power, and maximum plié depth during multiple grande jetés.

      Wyon, Matthew; Harris, Julie; Brown, Derrick; Clark, Frances (Science & Medicine, 2013-03)
      A lateral bias has been previously reported in dance training. The aim of this study was to investigate whether there are any bilateral differences in peak forces, power, and maximum knee flexion during a sequence of three grand jetés and how they relate to leg dominance. A randomised observational design was selected for the study. Volunteers consisted of 20 female dancers in the last year of pre-professional training. All volunteers completed three different tests to determine leg dominance prior to completing a three grande jeté sequence. The lead leg for the jump sequence was randomised. Peak take-off power, relative landing force (BW), and maximum knee flexion angles were measured using a Myotest accelerometer and integrated goniometer. Results indicated that 90% of dancers reported right leg dominance. A significant difference was noted in peak take-off power among the jumps (p<0.01); post hoc test indicated jump 3 was significantly greater than jump 1. Mean maximum take-off knee angles increased over the three-jump sequence with the left leg having a significantly deeper plié than the right (p<0.01). Landing data showed an increase in peak force and a decrease in maximum knee angles across the jump sequence. The present data indicate different bilateral strategies during take-off and landing during grand jetés in female dancers resulting in increased forces during the jumps on the non-dominant side. These differences need to be addressed by incorporating appropriate modifications in training methodology that eliminates the observed bilateral differences.
    • Biological evidence for the acute health effects of secondhand smoke exposure

      Flouris, Andreas D.; Vardavas, Constantine I.; Metsios, Giorgos S.; Tsatsakis, A. M.; Koutedakis, Yiannis (American Physiological Society, 2010)
      A vast number of studies on the unfavorable effects of secondhand smoke (SHS) exist within the international literature, the majority of which evaluate longitudinal epidemiological data. Although limited, the experimental studies that assess the acute and short-term effects of exposure to SHS are also increasing in number. They include cellular, animal, and human studies that indicate a number of pathophysiological mechanisms through which the deleterious effects of SHS may arise. This current review evaluates the existing biological evidence regarding the acute health effects of SHS exposure. Analyses on the inhaled toxicants and the carcinogenicity of SHS are included as well as in-depth discussions on the evidence for acute SHS-induced respiratory, cardiovascular, metabolic, endocrine and immune effects, and SHS-induced influences on oxygen delivery and exercise. The influence of the length of exposure and the duration of the observed effects is also described. Moreover, recent findings regarding the underlying pathophysiological mechanisms related to SHS are depicted so as to generate models that describe the SHS-induced effects on different systems within the human body. Based on the presented biological evidence, it is concluded that brief, acute, transient exposures to SHS may cause significant adverse effects on several systems of the human body and represent a significant and acute health hazard. Future research directions in this area include research on the concentrations of tobacco smoke constituents in the alveolar milieu following SHS exposure, individual susceptibility to SHS, as well as the effects of SHS on neurobehavioral activity, brain cell development, synaptic development, and function.
    • Body composition and ballet injuries: a preliminary study

      Twitchett, Emily; Angioi, Manuela; Metsios, Giorgos S.; Koutedakis, Yiannis; Wyon, Matthew A. (Hanley & Belfus, Inc, 2008)
      To date, the effects of body composition on injury occurrence and healing times in dancers have received limited scientific attention. The aim of the current study was to determine possible associations between somatotype, percent body fat, and self-reported injury characteristics in dance students. Forty-two full-time ballet students (11 male, 31 female) from two vocational dance schools volunteered for the study. The Heath-Carter protocol and Siri equation were adopted to calculate somatotype and percent body fat (%BF), respectively. Injury types, together with the time taken to recover from injury, were assessed using a recall injury questionnaire. Results revealed that the sample was classified as balanced-mesomorph somatotype (endomorphy – mesomorphy – ectomorphy = 3.4±0.9 – 3.9±1.4 – 3.2±1.2). Ectomorphy was a strong predictor of the number of acute injuries sustained (F1,36 = 5.4, p = 0.026); these parameters also revealed a significant negative correlation (r = –0.37, p = 0.016). Significant negative correlations were observed between the dancers’ total time off due to injury and %BF (r = –0.31, p = 0.048) and between the total time off resulting from acute injury and both %BF (r = –0.32, p = 0.04) and ectomorphy (r = –0.42, p = 0.005). The number of overuse injuries sustained and time off due to overuse injury also were correlated with mesomorphy (r = –0.38, p = 0.015 and r = –0.33, p = 0.032, respectively). It was concluded that high ectomorphy ratings, low %BF values, and low mesomorphy ratings are linked to injury. More relevant research is required on dancers from different genres.
    • Body mass index, nutritional knowledge, and eating behaviors in elite student and professional ballet dancers.

      Wyon, Matthew; Hutchings, Kate M; Wells, Abigail; Nevill, Alan M (Wolters Kluwer Health, 2014-09)
      Objective: It is recognized that there is a high esthetic demand in ballet, and this has implications on dancers' body mass index (BMI) and eating behaviors. The objective of this study was to examine the association between BMI, eating attitudes, and nutritional knowledge of elite student and professional ballet dancers. Design: Observational design. Setting: Institutional. Participants: One hundred eighty-nine participants from an elite full-time dance school (M = 53, F = 86) and from an elite ballet company (M = 16, F = 25) volunteered for the study. There were no exclusion criteria. Interventions: Anthropometric data (height and mass), General Nutrition Knowledge Questionnaire (GNKQ), and the Eating Attitude Test—26 (EAT-26) were collected from each participant. Main Outcome Measures: Univariate analysis of variance was used to examine differences in gender and group for BMI, GNKQ, and EAT-26. Regression analyses were applied to examine interactions between BMI, GNKQ, and EAT-26. Results: Professional dancers had significantly greater BMI than student dancers (P < 0.001), and males had significantly higher BMI scores than females (P < 0.05). Food knowledge increased with age (P < 0.001) with no gender difference. Student dancers had a significant interaction between year group and gender because of significantly higher EAT-26 scores for females in years 10 and 12. Regression analysis of the subcategories (gender and group) reported a number of significant relationships between BMI, GNKQ, and EAT-26. Conclusions: The findings suggest that dancers with disordered eating also display lower levels of nutritional knowledge, and this may have an impact on BMI. Female students' eating attitudes and BMI should especially be monitored during periods of adolescent development.
    • Bone mass of female dance students prior to professional dance training: A cross-sectional study

      Amorim, Tânia; Metsios, Giorgos S.; Nevill, Alan M.; Wyon, Matthew; Flouris, Andreas D.; Maia, José; Teixeira, E; Machado, José Carlos; Marques, Franklim; Koutedakis, Yiannis (PLOS one, 2017-07)
      Article Authors Metrics Comments Related Content Abstract Introduction Methods Results Discussion Conclusions Acknowledgments References Reader Comments (0) Media Coverage (0) Figures Abstract Background Professional dancers are at risk of developing low bone mineral density (BMD). However, whether low BMD phenotypes already exist in pre-vocational dance students is relatively unknown. Aim To cross-sectionally assess bone mass parameters in female dance students selected for professional dance training (first year vocational dance students) in relation to aged- and sex-matched controls. Methods 34 female selected for professional dance training (10.9yrs ±0.7) and 30 controls (11.1yrs ±0.5) were examined. Anthropometry, pubertal development (Tanner) and dietary data (3-day food diary) were recorded. BMD and bone mineral content (BMC) at forearm, femur neck (FN) and lumbar spine (LS) were assessed using Dual-Energy X-Ray Absorptiometry. Volumetric densities were estimated by calculating bone mineral apparent density (BMAD). Results Dancers were mainly at Tanner pubertal stage I (vs. stage IV in controls, p<0.001), and demonstrated significantly lower body weight (p<0.001) and height (p<0.01) than controls. Calorie intake was not different between groups, but calcium intake was significantly greater in dancers (p<0.05). Dancers revealed a significantly lower BMC and BMD values at all anatomical sites (p<0.001), and significantly lower BMAD values at the LS and FN (p<0.001). When adjusted for covariates (body weight, height, pubertal development and calcium intake), dance students continued to display a significantly lower BMD and BMAD at the FN (p<0.05; p<0.001) at the forearm (p<0.01). Conclusion Before undergoing professional dance training, first year vocational dance students demonstrated inferior bone mass compared to controls. Longitudinal models are required to assess how bone health-status changes with time throughout professional training.
    • Bone mass of female dance students prior to professional dance training: A cross-sectional study

      Amorim, Tânia; Metsios, George S.; Wyon, Matthew; Nevill, Alan M.; Flouris, Andreas D.; Maia, José; Teixeira, Eduardo; Machado, José Carlos; Marques, Franklim; Koutedakis, Yiannis (Plos, 2017-07-05)
      Summary According to existing literature, bone health in ballet dancers is controversial. We have verified that, compared to controls, young female and male vocational ballet dancers have lower bone mineral density (BMD) at both impact and non-impact sites, whereas female professional ballet dancers have lower BMD only at non-impact sites. Introduction The aims of this study were to (a) assess bone mineral density (BMD) in vocational (VBD) and professional (PBD) ballet dancers and (b) investigate its association with body mass (BM), fat mass (FM), lean mass (LM), maturation and menarche. Methods The total of 152 VBD (13 ± 2.3 years; 112 girls, 40 boys) and 96 controls (14 ± 2.1 years; 56 girls, 40 boys) and 184 PBD (28 ± 8.5 years; 129 females, 55 males) and 160 controls (27 ± 9.5 years; 110 female, 50 males) were assessed at the lumbar spine (LS), femoral neck (FN), forearm and total body by dual-energy X-ray absorptiometry. Maturation and menarche were assessed via questionnaires. Results VBD revealed lower unadjusted BMD at all anatomical sites compared to controls (p < 0.001); following adjustments for Tanner stage and gynaecological age, female VBD showed similar BMD values at impact sites. However, no factors were found to explain the lower adjusted BMD values in VBD (female and male) at the forearm (non-impact site), nor for the lower adjusted BMD values in male VBD at the FN. Compared to controls, female PBD showed higher unadjusted and adjusted BMDfor potential associated factors at the FN (impact site) (p < 0.001) and lower adjusted at the forearm (p < 0.001). Male PBD did not reveal lower BMD than controls at any site. Conclusions Both females and males VBD have lower BMDat impact and non-impact sites compared to control, whereas this is only the case at non-impact site in female PBD. Maturation seems to explain the lower BMDat impact sites in female VBD.
    • "Burnout” in Dance: the physiological viewpoint

      Koutedakis, Yiannis (International Association for Dance Medicine & Science, 2000)
    • Challenging habit: planning and preparation, the art of periodisation and optimising performance.

      Wyon, Matthew (Uitgeverij International Theatre and Film Books, 2004-01)
      A question to start - what is the goal, raison d’etre of a dance company? Hopefully you will agree that it is the performance, but a lot of current practice within the dance world is actually having the opposite effect. For example, rehearsing long hours right up to the start of a tour or performance; whilst on tour rehearsing all afternoon prior to an evening performance; the training focus being one-dimensional with too much emphasis on the technical aspects of dance and only paying lip service to the other components of performance. The concept of periodisation is to help optimise the preparation for performance for the dancers so they reach opening night mentally, physically and technically ready to perform. Needs analysis and planning is the key to good periodisation. And for that, co-operation between the different parties involved is vital, in addition to – of course – the basic will to challenge one’s own habits and to check out other knowledge can be useful for dance. Needs analysis refers to the examination of the possible demands that the performance is going to place on the dancer. Depending on how the piece is developed (experimentation, previously set etcetera) will determine the amount of prior knowledge of its demands is available to the planner. Hopefully the choreographer will have a broad concept of the piece and this will form the basis of initial plans, but the planner will need to be flexible. Some other questions that need to be answered are the extent of lifting, jumping, partner work within the piece, the length of time that the choreographer has to produce the work, the present physical, mental and technical condition of the dancers, the group dynamics of the company, the length of the performance period, the amount of travel that needs to be done. The planning component is the difficult part. The planner needs to decide on the importance of all the different components of the `whole’ that makes up performance preparation and then decide how to organise and prioritise them; within this need to be included rest and travel days. The main thing to remember is to work backwards from the start of the performance period and this is where some controversies begin.
    • Changes in Energy Demand of Dance Activity and Cardiorespiratory Fitness During One Year of Vocational Contemporary Dance Training

      Beck, Sarah; Wyon, Matthew A; Redding, Emma (Wolters Kluwer, 2017-11)
      Previous literature has demonstrated that the intensity of dance class, as well as its discontinuous nature, is not sufficient to elicit an aerobic training response and that the aerobic capacity of dancers is relatively low. These findings have raised questions of the suitability of training, through class and rehearsal, as adequate preparation for the physical demands of performance and a sustained, successful career in dance. The aim of this study was to describe changes in aerobic fitness and energy cost of dance movement occurring throughout one year of training. Subjects were thirteen female dance students; seven first year undergraduate students (UG), and six postgraduate students (PG). At three time-points (TP1, TP2, TP3) during one academic year each subject completed a treadmill test, to determine VO2peak (ml.kg-1.min-1) and lactate threshold (LT) (ml.kg-1.min-1 and %VO2peak), and a standardised four-minute dance sequence, where mean demand was expressed as VO2 (ml.kg-1.min-1), heart rate (b.min-1), %VO2peak, and %LT. Both groups displayed an overall decrease in mean VO2peak throughout the year, despite a peak in fitness at TP2 in the PG students. No significant changes in LT were noted over time for either group. A significant reduction in the relative intensity of the dance sequence, particularly in relation to mean VO2 (ml.kg-1.min-1) and %LT data, was observed over time in both groups although the degree of change was less in the UG group than the PG group. Apparent adaptations during a rehearsal period in the PG group are presented in contrast to previous research findings. Recommendations for future research include further investigation into the energy demand of rehearsal and cardiorespiratory adaptation during rehearsal periods as well as further reporting of measures related to LT and movement economy.
    • Clinical anatomy and biomechanics of the ankle in dance.

      Russell, Jeffrey A.; McEwan, Islay M.; Koutedakis, Yiannis; Wyon, Matthew A.; University of Wolverhampton School of Sport, Performing Arts and Leisure, Walsall, United Kingdom. jrussell@kardia.org (J. Michael Ryan, 2008)
      The ankle is an important joint to understand in the context of dance because it is the connection between the leg and the foot that establishes lower extremity stability. Its function coordinates with the leg and foot and, thus, it is crucial to the dancer's ability to perform. Furthermore, the ankle is one of the most commonly injured body regions in dance. An understanding of ankle anatomy and biomechanics is not only important for healthcare providers working with dancers, but for dance scientists, dance instructors, and dancers themselves. The bony architecture, the soft tissue restraints, and the locomotive structures all integrate to allow the athletic artistry of dance. Yet, there is still much research to be carried out in order to more completely understand the ankle of the dancer.
    • Dance biomechanics: a tool for controlling health, fitness, and training.

      Koutedakis, Yiannis; Owolabi, Emmanuel O.; Apostolos, Margo (J. Michael Ryan, 2008)
      The need for superior performance in dance has impelled teachers and choreographers to use increasingly effective and sophisticated methods of preparation. To that end, such modalities ofbiomechanics as advanced motion-capture, muscle-function and muscle-strength techniques are being used to provide useful information about which of the dancers' needs require special attention. This often involves improving aspects of dance technique, which, in turn, may help dancers to prevent disabling injuries, the most frequent cause of notoriously short dance careers. Biomechanics may also help dancers to assess fitness levels, to control overtraining or "burnout," and assist them and their teachers in the effective scheduling of practice and exercise sessions.
    • Electrocardiography and Echocardiography Findings in Contemporary Dancers

      Whyte, Gregory P.; George, Keith; Redding, Emma; Wilson, Mathew; Lane, Andrew M.; Firooz, Sam (International Association for Dance, Medicine and Science, 2003)
      Alterations in cardiac structure and function as a result of chronic training have been extensively reported in the literature. To date, there is limited data on dancers. This study attempts to define cardiac electrical, structural, and functional characteristics of the heart in female contemporary dancers. Forty-four female full-time contemporary dance students (age: 23.0 ± 5.6 years, height: 165.2 ± 7.9 cm, body mass: 59.2 ± 7.2 kg) volunteered for the study and underwent 12-lead electrocardiography and twodimensional echocardiography. Echocardiographic results were compared with 30 age-matched and gendermatched controls. Sixteen percent (7/ 44) of dancers presented with sinus bradycardia (< 60 bpm) and seven percent (3/44) demonstrated shortened PR intervals (< 120 ms). Sokolow voltage criteria for left ventricular hypertrophy was observed in only 4% (2/44). Fourteen percent of dancers (6/44) demonstrated right axis deviation and nine percent (4/44) had incomplete right bundle branch block. One dancer exhibited nodal rhythm. Minor ST segment elevation (< 0.2 mV) was present in 7% (3/ 44) of dancers, and equally minor ST segment depression (£ 0.2 mV) was present in 7% (3/44). Negative T waves and large T waves (>1.0mV) were observed in 14% (6/44) and 4% (2/44) of the dancers respectively. QRS and QT duration were within normal limits for all dancers. Echocardiography revealed no significant differences between dancers and controls for all structural and functional indices. It is concluded that contemporary dancers demonstrate limited cardiac structure and function changes compared to matched controls.
    • Fit to dance survey: a comparison with dancesport injuries.

      Riding McCabe, Teri; Ambegaonkar, Jatin P; Redding, Emma; Wyon, Matthew (Science & Medicine, 2014-06)
      The Fit to Dance survey has been conducted twice previously, in 1993 and 2002, without dancesport participants. The purpose of this present online survey was to supplement a comparison of dancesport against the earlier results. The current study had a greater percentage of male respondents than previous studies (43% vs 24% and 26%). The dancesport participants were older (28% at 40+ yrs vs 3% and 1%) and more likely to have normal (69% vs 57%) to overweight BMI (18% vs 2%). Dancesport participants spent more time in various non-dancing conditioning activities than previous surveys (5.2 ± 3.9 hrs SD vs 1.9 ± 2.5 and 2.2 ± 2.7). Muscles and joints were the most common type of injury in all the surveys. The knee was the top injury site in this survey, with lower back in previous surveys. The main perceived cause of injury was repetitive movements, whereas fatigue and overwork were cited in the previous surveys. Physiotherapists were the most common type of medical professionals from whom the dancers sought treatment for their injuries in all surveys. The first survey included recommendations that the present survey results agree with, including: dancers should be physically fit, dancers should warm up and cool down, dancers should never have to work in unsuitable environments, and dancers should receive immediate high-quality treatment for injuries.
    • Isokinetic characteristics of knee flexors and extensors in male dancers, olympic oarsmen, olympic bobsleighers, and non-athletes

      Koutedakis, Yiannis; Agrawal, Arvind; Sharp, N. C. Craig (J. Michael Ryan, 1998)
      Quadriceps (PTQUAD) and hamstring (PTHAM) concentric peak torques — measured in Nm and Nm·kg-1 body weight — and hamstring/quadriceps peak torque ratios (PTHAM/QUAD) were studied in males engaged in different physical activities and having different levels of physical fitness. Both dominant and non-dominant legs of 20 professional dancers, 14 Olympic oarsmen, 11 Olympic bobsleighers, and 10 non-athletes were isokinetically assessed at 1.04, 3.14, and 4.19 rad·sec-1. The main findings were: 1. torque levels decreased with increasing angular velocity in all four groups of subjects; 2. with few exceptions, dancers and non-athletes demonstrated significantly lower PTQUAD and PTHAM (p < 0.01 to p < 0.005) at the three velocities than bobsleighers and rowers; 3. most of the differences between groups described above, disappeared (p > 0.05) when PTQUAD and PTHAM were standardized for body weight (Nm·kg-1); and 4. although PTHAM/QUAD for dancers and non-athletes were significantly lower than that of the two sports groups at 1.04 and 3.14 rad·sec-1, no such differences were noted at the relatively higher velocity of 4.19 rad·sec-1. We conclude that dissimilar physical training, modes of exercise, and/or different fitness levels have the same effect on muscle contractile characteristics.