bluuebunny/crossref_metadata_2025 huggingface dataset:
Rate of Change in 10-Year Atherosclerotic Cardiovascular Disease Risk and Its Implications for Primary Prevention
Authors: Hwang In-Chang , Kim Chee Hae , Kim Jae-Young , Choi Hong-Mi , Yoon Yeonyee E. , Cho Goo-Yeong
Published: May 2023

BACKGROUND:

Contemporary cardiovascular primary prevention is based on the assessment of the 10-year risk of atherosclerotic cardiovascular disease (ASCVD). However, the clinical implications of temporal change in the 10-year ASCVD risk estimate (∆10-year ASCVD risk/year) are unknown.

METHODS:

A total of 211 077 participants without established ASCVD and with repetitive 10-year ASCVD risk assessment at an interval of 4 to 5 years were selected from the Korean National Health Insurance Service data. The primary end point was a composite of myocardial infarction, stroke, coronary revascularization, and all-cause death.

RESULTS:

ASCVD event rates were proportional to the ∆10-year ASCVD risk/year regardless of the baseline 10-year ASCVD risk. Adjusted hazard ratio for ASCVD events per 1% increase in ∆10-year ASCVD risk/year was 1.53 (95% CI, 1.44–1.63), 1.24 (95% CI, 1.15–1.32), 1.18 (95% CI, 1.13–1.23), and 1.05 (95% CI, 1.00–1.10) in those with a baseline 10-year ASCVD risk of <5%, 5% to 7.5%, 7.5% to 20%, and ≥20%, respectively. Appropriate control of risk factors, including low-density lipoprotein cholesterol, blood pressure, body mass index, exercise habits, and smoking status, was associated with lower ASCVD event rates, whereas failure to control these risk factors resulted in higher ASCVD event rates.

CONCLUSIONS:

The temporal change in 10-year ASCVD risk over a period of 4 to 5 years reflects success or failure in controlling major cardiovascular risk factors and indicates the risk of future ASCVD events. The ∆10-year ASCVD risk/year can be used as an indicator of primary prevention and guide the application of preventive measures.
Two new species of the genus Nicephora Bolívar, 1900 (Orthoptera: Tettigoniidae: Meconematinae) from Yunnan, China
Authors: SU JIE , WANG HAIJIAN , CHANG YANLIN
Published: May 2023

This paper reports two new species of the tribe Meconematini from Yunnan, China, namely Nicephora curvata sp. nov. and Nicephora angustifolia sp. nov., and diagnostic illustrations are provided. The type specimens are deposited in the Museum of Hebei University.
Association Between Sleep and Cognition of Older Adults in Rural Areas: A Cross-Sectional Study
Authors: Meng Wenjia , Gao Tianlin , Zhong Yang , Ge Ling
Published: May 2023

Sleep is an essential physiological function for everyone. Limited evidence existed on the associations between multi-factor sleep patterns and cognition among older adults in rural areas. Aimed to assess that, We conducted a cross-sectional study on the living habits and cognitive status in rural areas of Qingdao and 1167 participants aged 65 to 96 years answered the questionnaire. The result showed that poor sleep quality, high sleep disturbance, daytime dysfunction, and hypnotic drug-dominated sleep patterns were related to the cognitive function, and there was no obviously associations between good sleep duration and cognition. In order to solve the sleep problems and preserve cognitive function, support and protection of physical and mental health should be the priority of government policies in helping older adults’ group in rural areas.
Future Systems of Xenotransplantation: Melding Historical and Bioethical Methodology
Authors: Negri Adam , Wilson Lauren
Published: May 2023

The future of xenotransplantation is promising. However, the scientific process behind xenotransplantation, shown through the methodology of history and bioethics, involves stakeholders beyond the laboratory. We present three short vignettes, the history of a 20th-century pioneer in solid organ transplantation, the xenoheart received by David Bennett, and a global system of illegal organ procurement, to highlight the complexity of biomedical practice. Current solid organ transplantation systems are seemingly unsustainable and ineffective in satisfying a growing global demand for organs. Despite the shortcomings of current systems, we argue that the discourse surrounding xenotransplantation science is insufficient to construct a long-lasting and equitable replacement for solid organ transplantation. Xenotransplantation is more than a surgical technique, an interdisciplinary health concern, or a biomedical technology—it is deeply dependent on a series of cultural, historical, and social factors. Incorporating a greater variety of perspectives and disciplines into ongoing discussions of xenotransplantation science, while potentially frustrating in the short term, will act to maximize its potential as a paradigm-shifting science.
Drafting behind LGB: Transgender athletes in the sport of cycling
Authors: Hardwicke Jack , Roberts Charlie J , Anderson Eric , Magrath Rory
Published: May 2023

Using data from an online survey of 211 heterosexual and 148 sexual and gender minority-identifying cyclists, this article examines the attitudes of both sexual and gender majorities towards sexual and gender minorities as well as the experiences of sexual and gender minorities in relation to each other, within the sport of cycling. The results show a culture of acceptance for LGB athletes with heightened antipathy towards transgender cyclists. However, this variance is not as large as might be expected given the media attention on transgender athletes in cycling, and sport more broadly. It therefore appears that the transgender social movement is drafting closely behind LGB inclusion within this sport.
Foreign Language Learning and Learning Disabilities: An Historical, Empirical, and Cultural Perspective for Policies and Procedures
Authors: Sparks Richard L.
Published: May 2023

Twenty-five years ago, the author contributed a historical review of evidence on the foreign language (FL) learning problems of low-achieving and learning disabled (LD) students. Educators had proposed a new disability, FL learning disability, and developed policies permitting LD students to substitute courses or waive the FL requirement. The introduction of this new disability was premature because empirical evidence found no relationship between FL learning problems and LDs. Even so, several misguided assumptions about a unique disability for FL learning and a special relationship between FL learning problems and LDs persisted, and an LD diagnosis became the de facto criterion for FL course substitution/waiver policies. In this updated review, these assumptions and evidence falsifying them are examined. Cultural reasons for the assumptions about FL learning and LDs and the adoption of course substitution policies are proposed. The author concludes with recommendations for policymakers.
Implant Choice and Outcomes of the Sinus Tarsi Approach for Displaced Intra-articular Calcaneal Fractures
Authors: Eelsing Robin , Aronius Loran B. , Halm Jens A. , Schepers Tim
Published: May 2023

Background:

Operative fixation of displaced intra-articular calcaneal fractures is considered the gold standard, for which multiple fixation methods are available. This study compares the (functional) outcome of screw fixation (SF), plate fixation (PF), and anatomical plate fixation (APF) via the sinus tarsi approach (STA).

Methods:

A total of 239 patients (265 fractured calcanei) who received surgical treatment of a displaced intra-articular calcaneal fracture via STA between 2011 and 2022 were included.

Results:

Böhler angle (BA) measured immediately postoperatively (BA post-OR) and the decrease in BA at 1 year (∆BA) differed significantly in favor of PF/APF compared with SF (BA post-OR: SF vs PF P = .010 and SF vs APF P = .001; ∆BA: SF vs PF P = .032 and SF vs APF P = .042). Implant removal surgery was performed significantly less in the APF group as compared to the SF/PF groups (APF vs SF/PF; 9.9% vs 22.9%/23.7%, P = .015). Surgical site infections and secondary arthrodesis of the subtalar joint occurred equally in the 3 groups. Furthermore, the mean American Orthopaedic Foot & Ankle Society ankle-hindfoot scale, Foot Function Index score, and EuroQOL-5D-index / visual analog scale score, did not differ notably between SF, PF, and APF.

Conclusion:

The results show that both PF and APF are favored over SF because of an improved correction of BA measured directly postoperatively, a lower secondary loss of BA and, for APF, a lower implant removal rate. There was no difference in the rate of surgical site infections, need for secondary arthrodesis, nor functional outcome scores between different implants using the STA.

Level of Evidence:

Level III, retrospective cohort study.
Simulation study on the flow-induced vibration and noise in marine centrifugal pumps
Authors: Zhao Cunsheng , Chai Kai
Published: May 2023

Due to the three-dimensional non-axisymmetric shape of the volute, its interaction with the impeller increases the internal flow field complexity and instability of the marine centrifugal pump, representing the main reason for pump body vibration and hydraulic noise. First, the basic principle of fluid machinery noise calculation was explained based on the Lighthill acoustic analogy method and Curle’s theory. Then, the fluid pressure pulsation and flow characteristics of centrifugal pumps were analyzed using the Fluent software, after which the Actran software was used to examine the flow-induced vibration noise properties. The results showed that the clearance size significantly impacted the pump head, while the peak value of the flow-induced vibration response was mainly twice the blade frequency. Although a larger ring clearance increased the structural vibration, it had little impact on the sound pressure level changes in the external sound field. The results provided a new method for the structural optimization and low-noise design of marine centrifugal pumps.
Electromyographic Comparison of the Développé Devant at Barre and Centre
Authors: Wilmerding M. Virginia , Heyward Vivian H. , King Molly , Fiedler Kurt J. , Stidley Christine A. , Pett Stuart B. , Evans Bill
Published: May 2023

This investigation compared the electromyographic (EMC) activity of selected muscle groups of skilled dancers executing the développé devant at barre and in centre. A four-channel Nicolet-Viking Biomedical electrograph system was used to assess muscular activity. Surface electrodes were placed over four muscles: quadriceps femoris, hamstrings, tibialis anterior, and abductor hallucis. The participants performed five trials of the développé devant at barre and centre in randomized order. The dancers performed the six phases of the développé devant (coupé, passé, attitude, full extension, tendu, closure to fifth position) in time with a metronome set in three-quarter time at 144 beats per minute. EMC amplitude was recorded at each of the six time phases (1200, 2400, 3600, 4800, 6000, and 7200 msec, respectively). The EMC values (mV) of the raw amplitude of each phase of the développé devant for each subject were “standardized” by dividing by their respective maximum voluntary contraction (MVC). A four-way ANOVA was used to assess the effects and interactions of subjects, trials, phases, and “treatment” (barre versus centre). Results indicated no significant difference (p < 0.05) between barre and centre for either the quadriceps femoris or hamstring muscle of the gesture leg. The main effect of phase was significant (p < 0.05). There was a significant difference in EMC activity (p < 0.05) between barre and centre for the tibialis anterior and abductor hallucis of the standing leg across phases. Post-hoc analysis indicated that EMC activity of the tibialis anterior and abductor hallucis muscles was significantly greater at centre compared to barre during all phases of the développé devant. It was concluded that the training at barre is an acceptable way of preparing the muscles of the gesture leg, but not the standing leg, for the demands of centre.
Adolescent Issues in a Psychological Approach to Dancers
Authors: Lee Susan A.
Published: May 2023

To date, surprisingly little literature in the field of dance medicine and science has addressed the psychological needs and struggles of the large number of adolescents who participate in dance at all levels. This essay identifies some critical issues in contemporary adolescent development in the context of the dance world. The “normal” or predictable tasks of adolescence are detailed. Relevant research on dancers is reviewed. From a psychological perspective, dance professionals are challenged to examine their practices as educators and mentors in supporting this important life course passage.
The Effect of Spinal and Pelvic Posture and Mobility on Back Pain in Young Dancers and Non-Dancers
Authors: McMeeken Joan , Tully Elizabeth , Nattrass Caroline , Stillman Barry
Published: May 2023

One-hundred-and-twenty healthy volunteers (ranging in age from 10 to 25 years), completed a questionnaire concerning the type and amount of regular activity and history of low back pain. There were 41 who participated in at least 6 hours of dance per week and 79 non-dancers. Computer-based analysis of videotape records examined sagittal standing posture and thoracolumbar flexion-extension mobility On average, dancers undertook 19 h/wk more regular activity (p = 0.0001), were lighter by 7 kg (p = 0.001), had straighter standing postures (p < 0.001) and greater thoracic and lumbar sagittal excursions (by 23° and 9°, respectively) (p < 0.01). One or more episodes of back pain of at least two days duration was experienced by 24% of all subjects in the past year, and 18% recalled at least one episode of back pain in earlier years. Dancers experienced significantly more back pain in the last year, and in earlier years, compared to non-dancers (37% versus 18% and 24% versus 14%, respectively), but the relative incidence of back pain expressed as hours of activity per incident was less for dancers (1:20 hours) than non-dancers (1:5 hours). The non-dancers who experienced pain had more flexed lumbar spine standing postures (p = 0.01), and a direct correlation between lumbar spine excursion and severity of the worst pain episode over the previous year (p = 0.02).
A Primer on Measuring Dancer Capacities
Authors: Welsh Thomas M.
Published: May 2023

The reliable, valid, and sensitive measure-ment of dancer capacities is essential to dance medicine and science research, clinical practice, and dancer training. The unique nature of dance and the unusual demands it places on dancers present spe-cial challenges for measuring dancer ca-pacities. The contributions in this and the next issue review measurement strategies for several capacities important to dancers. This article describes measurement characteristics common to the variety of disciplines encompassed by dance medicine and science. It concludes with a description of possible benefits for evolving standardized measures of important dancer capacities.
The Relationship between Passion and Injury in Dance Students
Authors: Rip Blanka , Fortin Sylvie , Vallerand Robert J.
Published: May 2023

The present study explored whether dancers exhibit distinct injury profiles and injury-related coping behaviors as a function of their passion for dance. Results from 81 student dancers suggest that having a harmonious passion for dance is associated with suffering less from acute injuries, exhibiting more problem-focused health-promoting and less health-undermining coping behaviors when injured, being more flexibly involved in dance activities when injured, and engaging in self-initiated injury prevention. Obsessive passion for dance, on the other hand, is associated with prolonged suffering from chronic injuries, more rigid involvement in dance activities when injured, and the tendency to report that pride is a major factor preventing one from obtaining adequate treatment. Thus, it appears that obsessive passion for dance may constitute a risk factor for sustaining chronic injuries, and that harmonious passion is the more optimal motivational foundation for long-term, healthful involvement in dance.
The Development of Imagery in Dance: Part I: Qualitative Findings from Professional Dancers
Authors: Nordin Sanna M. , Cumming Jennifer
Published: May 2023

A series of two studies was undertaken to investigate the development of imagery among dancers and how dance teachers might affect the imagery development process. The first study is reported here, the second in Part II. For the present study, in-depth semi-structured interviews were conducted with 14 female (n = 9) and male (n = 5) professional dancers from a range of ages and dance forms. The recorded interviews were transcribed verbatim and content-analyzed with NVivo 4.0. Results fell into three categories: Early Experiences, Teachers, and Imagery Changes. Findings included few dancers having been taught about imagery, and that dancers often preferred teachers who gave plenty of images so that each dancer could use images that suited his or her own needs. As dancers became more accomplished, imagery typically changed toward more frequent, complex, and kinesthetic images. Suggestions for further research and ideas for practical application are provided.
Analysis of the Hip Joint Moments in Grand Rond de Jambe en l'Air
Authors: Kwon Young-Hoo , Wilson Margaret , Ryu Joong-Hyun
Published: May 2023

The purpose of this study was to investigate hip net joint moments in the gesture and support legs in grand rond de jambe en l'air en dehors. Two groups of dancers, skilled (N = 8) and novice (N = 6), performed grand rond de jambe en l'air at two different vertical leg angles: 90° and 105°. Three-dimensional motion data and ground reaction force data were collected. Hip net joint moments were computed through standard inverse dynamics procedures and were normalized to each participant's mass. Normalized peak hip joint moments in both the gesture and support leg were used as the dependent variables; the independent variables were the skill level and the demand (vertical angle for the rond de jambe at 90° and 105°). A two-way mixed-design ANOVA (2 groups x 2 conditions) was used (p < .05) with the group and demand as the between and within factors, respectively. The hip joint moments of the support leg were consistently larger than the matching moments of the gesture leg. However, as the demand level increased the peak hip joint moments of the gesture leg hip showed minor changes, the support leg moments decreased. It was concluded that muscular strength is not a limiting factor for the novice dancers and that an increased demand (vertical leg angle) actually puts smaller burden on the support leg hip. Increased pelvis movement (demonstrated by the skilled dancers) facilitated the range of motion of the gesture leg without increasing joint moment cost. The hip abductor moments were identified as im-portant components in performing grand rond de jambe en l'air.
Dancing through Pregnancy: Activity Guidelines for Professional and Recreational Dancers
Authors: Sanders Sarah G.
Published: May 2023

Over the past few years the benefits of exercise during pregnancy have become appreciated. Much attention has been given to common forms of exercise, such as aerobic dance, swimming, cycling and running. The effects of professional and recreational dance during pregnancy, such as ballet or flamenco, for example, have not been explored. Many studies, however, address issues relevant to dance. The purpose of this article is to delineate as clearly as possible what dance activities are safe and even possibly beneficial for the mother and her baby, as well as those activities and levels of exertion that should be avoided.
A Profile of the Demographics and Training Characteristics of Professional Modern Dancers
Authors: Weiss David S. , Shah Selina , Burchette Raoul J.
Published: May 2023

Modern dancers are a unique group of artists, performing a diverse repertoire in dance companies of various sizes. In this study, 184 professional modern dancers in the United States (males N=49, females N = 135), including members of large and small companies as well as freelance dancers, were surveyed regarding their demographics and training characteristics. Te mean age of the dancers was 30.1 ± 7.3 years, and they had danced professionally for 8.9 ± 7.2 years. Te average Body Mass Index (BMI) was 23.6 ± 2.4 for males and 20.5 ± 1.7 for females. Females had started taking dance class earlier (age 6.5 ± 4.2 years) as compared to males (age 15.6 ± 6.2 years). Females were more likely to have begun their training in ballet, while males more often began with modern classes (55% and 51% respectively, p < 0.0001). Te professional modern dancers surveyed spent 8.3 ± 6.0 hours in class and 17.2 ± 12.6 hours in rehearsal each week. Eighty percent took modern technique class and 67% reported that they took ballet technique class. Te dancers who specified what modern technique they studied (N = 84) reported between two and four different techniques. The dancers also participated in a multitude of additional exercise regimens for a total of 8.2 ± 6.6 hours per week, with the most common types being Pilates, yoga, and upper body weightlifting. The dancers wore many different types of footwear, depending on the style of dance being performed. For modern dance alone, dancers wore 12 different types of footwear. Reflecting the diversity of the dancers and companies surveyed, females reported performing for 23.3 ± 14.0 weeks (range: 2-52 weeks) per year; males reported performing 20.4 ± 13.9 weeks (range: 1-40) per year. Only 18% of the dancers did not have any health insurance, with 54% having some type of insurance provided by their employer. However, 23% of the dancers purchased their own insurance, and 22% had insurance provided by their families. Only 16% of dancers reported that they had Workers' Compensation coverage, despite the fact that they were all professionals, including many employed by major modern dance companies across the United States. It is concluded that understanding the training profile of the professional modern dancer should assist healthcare providers in supplying appropriate medical care for these performers.
Communication between Medical Practitioners and Dancers
Authors: Ruanne Y. J. Lai , Krasnow Donna , Thomas Martin
Published: May 2023

The purpose of this study was to investigate patterns of communication between professional and pre-professional dancers and medical practitioners. One survey was developed and randomly conducted among family physicians, sports medicine physicians, chiropractors, physical therapists, and registered massage therapists. A second survey involved volunteer ballet and modern dancers in professional dance training programs, college and university dance programs, and independent dance artists. One hundred and ninety questionnaires were distributed to medical practitioners, and 50 were returned. Of 380 questionnaires given to dancers, 202 were returned. The dancers were 18 to 49 years old, with a majority between the ages of 18 and 20. They averaged more than 10 years of dance training. All of the questionnaires were distributed in a single large Canadian city.

The data shows that medical practitioners rarely communicated with each other concerning a common (dance) patient. They also failed to communicate, in most cases, with the dancers’ teachers, choreographers, and directors. This was not disconcerting to injured dancers, who tended to believe that such communication was not important to their recovery. Significantly, dancers did not fully understand the nature of their injuries when they sought medical advice, and they did not press the medical practitioners for additional information. Both groups generally believed that dancers would benefit by learning more about human anatomy.
Knee and Ankle Strength and Lower Extremity Power in Adolescent Female Ballet Dancers
Authors: Kenne Ellinor , Unnithan Viswanath B.
Published: May 2023

The aims of this study were twofold: 1. to compare the strength of four muscle groups of the lower limb (quadriceps [Q], hamstrings [H], plantar flexors [PF], and dorsiflexors [DF]) between female adolescent ballet dancers (BALs) and basketball players (BBs) over three angular velocities (30°, 60° and 90°/sec) and two types of contraction (eccentric and concentric); and 2. to compare peak and mean power between the BALs and BBs. Eleven BALs (age: 15.8 + 1.2 years; stature: 163.9 ± 6.2 cm; body mass: 56.3 + 5.7 kg; Tanner stage 4: N = 10, stage 5: N = 1) and ten BBs (age: 15.8 + 1.0 years; stature: 172.5 + 5.8 cm; body mass: 63.2 + 10.0 kg; Tanner stage 4: N = 7, stage 5: N = 3) volunteered to participate. Each participant performed one habituation session and one testing session on a Biodex isokinetic dynamometer to determine peak torque. Three angular velocities (30°, 60° and 907sec) were used for each muscle group. To determine absolute and relative peak and mean power, participants performed a 30 second anaerobic Wingate test on a cycle ergometer. There were no significant differences in peak torque for Q, H, PF, and DF between the groups. Basketball players produced greater absolute peak power [569.7 ± 82.2 vs. 454.6 ± 79.3 W (p < .05)], relative peak power [9.1 ± 1.3 vs. 8.1 ± 1.0 W/kg body mass (p < .05)], absolute mean power [428.4 ± 53.9 vs. 333.7 ± 68.2 W (p < .05)] and relative mean power [6.83 ± 0.7 vs. 5.9 ± 0.7 W/kg (p < .05)] than BALs. Ballet dancers and BBs had similar isokinetically measured lower extremity muscular strength, but BALs generated lower levels of peak power and mean power compared to BBs.
The Development of a High Intensity Dance Performance Fitness Test
Authors: Redding Emma , Weller Peter , Ehrenberg Shantel , Irvine Sarah , Quin Edel , Rafferty Sonia , Wyon Matthew , Cox Carol
Published: May 2023

While there is currently a validated dance-specific exercise method of measuring aerobic fitness, no such test has been developed to measure high intensity capabilities in dance. The purpose of this study was to initiate an intermittent high intensity dance-specific fitness test. The test was designed to be able to observe changes in heart rate (HR), thereby allowing for a measurement of physical fitness at high intensities. Sixteen professional dancers (4 males and 12 females) volunteered to take part in this study. The fitness test protocol consists of movements that are representative of contemporary dance, and contains exercise and rest periods that mimic the intermittent nature of dance. The participants performed four trials. The physiological variables measured were HR (b·min-1) for each one minute bout of the four minute test for all trials, oxygen uptake (VO2) throughout the test, and end blood lactate (BLa mmol·L) for each trial. In addition, five of the participants undertook a maximal oxygen uptake treadmill test, and the scores obtained were compared with those from the dance test. Results show HR consistency across each one minute bout of the test and across each of the four trials of testing for all participants, indicating that the test is reliable. There was good reliability between bouts of each trial (typical error as % of CV = 1.5), intraclass “r” = 0.8, and good reliability between the four trials (typical error as % of CV =2.1), intraclass “r” = 0.82. There were no significant differences between the maximal VO2and BLa scores established in the treadmill and dance tests, demonstrating validity. Thus, the results of this study indicate that the high intensity dance-specific test is a reliable and valid means of assessing and monitoring the cardiovascular fitness of dancers. The test allows dancers to be assessed within an environment that they are accustomed to (the studio), using a mode of exercise that is relevant (dance), and it is of adequate intensity to be representative of performance.
Screening Program for Dancers Administered by Dancers
Authors: Wilson Margaret , Deckert Jennifer L.
Published: May 2023

Students enrolled in a dance kinesiology class were trained to administer a screening protocol on younger dancers in the same department. The dance kinesiology students gained experience assessing alignment and functional symmetry in their peers, and then recommended exercises for gaining awareness and developing balanced patterns of movement. This “low stakes” assessment created both dialogue and peer support centered on helping the screened dancers understand and effectively work with their individual capacities and limitations. The project was designed to contribute to a culture of wellness and education within the dance department.
Risk Factors for Lower Back Injury in Male Dancers Performing Ballet Lifts
Authors: Alderson Jacqueline , Hopper Luke , Elliott Bruce , Ackland Tim
Published: May 2023

Lower back injuries are common in ballet dancers. Allegedly there is a higher incidence in males than in females due to their lifting requirements. This study analyzes the estimated forces generated at the L5/S1 joint in five professional and three pre-professional male dancers performing full press (FP) and arabesque (AR) ballet lifts. The estimated peak lumbar anterior shear force (PLASF) was identified using a 3D motion analysis system, and was found to occur at the beginning of each lift, approximately 0.01 seconds prior to the ballerina moving vertically into the lift. Data representing the male dancers’ posture at the point of PLASF were input into a 3D Static Strength Prediction Program (3DSSPP, University of Michigan, Centre for Ergonomics, 2006) to calculate the PLASF and corresponding compression forces. The compression forces identified in this way were found to be greater than the National Institute of Occupational Safety and Health, Back Compression Design Limit (3400N). This suggests that administrative controls such as monitoring the number of lifts performed daily are required to reduce the risk of lower back injury in male dancers. Comparison of the two lifts found significantly (p < 0.05) higher compression forces in the FP versus the AR lift. This could be attributed to a significantly (p < 0.05) larger horizontal distance between the male dancer and the ballerina, or the eccentric loading of the male dancers’ lower limb and trunk musculature in the preparation phase of the FP. Retrospective regression analysis indicated that peak trunk extension velocity and the horizontal distance between the male dancer and the ballerina were significant (p < 0.05) predictors of PLASF.
A Test for Evaluating Proficiency in Dance
Authors: Chatfield Steven J.
Published: May 2023

This study assessed the inter-judge agreement, intra-judge reliability, and the specificity and sensitivity of a qualitative test for analyzing dancers’ training and performance capabilities. Forty-one subjects representing groups of non-dancers (N = 9), beginners (N = 9), intermediates (N = 10), advanced (N = 7), and professionals (N = 6) were videotaped while performing compulsory and improvised segments of movement. The videotapes were then analyzed by three trained judges, using the unique scoring system devised by the author, for the following components: skill, space, time, energy, phrasing, and presence. Inter-judge agreement correlations and the overall intra-judge reliability coefficient were very high (r = .95 to .96, p < .0001, and R = .98, p < .0001, respectively). Specificity was .86, and sensitivity .97. It is concluded that the test described in the study is valid for use in both research and educational settings where qualitative analysis of dance performance across levels of expertise is useful.
Calculation of Muscle Loading and Joint Contact Forces during the Rock Step in Irish Dance
Authors: Shippen James M. , May Barbara
Published: May 2023

A biomechanical model for the analysis of dancers and their movements is described. The model consisted of 31 segments, 35 joints, and 539 muscles, and was animated using movement data obtained from a three-dimensional optical tracking system that recorded the motion of dancers. The model was used to calculate forces within the muscles and contact forces at the joints of the dancers in this study. Ground reaction forces were measured using force plates mounted in a sprung floor. The analysis procedure is generic and can be applied to any dance form. As an exemplar of the application process an Irish dance step, the rock, was analyzed. The maximum ground reaction force found was 4.5 times the dancer's body weight. The muscles connected to the Achilles tendon experienced a maximum force comparable to their maximal isometric strength. The contact force at the ankle joint was 14 times body weight, of which the majority of the force was due to muscle contraction. It is suggested that as the rock step produces high forces, and therefore the potential to cause injury, its use should be carefully monitored.
Lateral Bias, Functional Asymmetry, Dance Training and Dance Injuries
Authors: Kimmerle Marliese
Published: May 2023

The purpose of this article is to: 1. provide a conceptual framework for consolidating laterality research in dance training from an interdisciplinary perspective; 2. encourage the reporting of lateral data; 3. promote the development of standardized methods for assessing lateral preference and functional asymmetry so that data sets from student screenings, lab studies, and injury reports can be compared; and 4. stimulate further laterality research in the dance studio to examine student preference and teaching bias, thereby promoting balanced training.
Trait Anxiety and Achievement Goals as Predictors of Self-Reported Health in Dancers
Authors: Lench Heather C. , Levine Linda J. , Roe Elisa
Published: May 2023

Psychological characteristics associated with interpreting situations as stressful can impact peoples physical health. The present investigation focused on trait anxiety and achievement goals as two such characteristics that may predict health outcomes in dancers, a group prone to chronic stress and injury. Students enrolled in a university dance program (N = 109) completed measures of trait anxiety, achievement goals for dance classes, and current health at the start of an academic term. Health was assessed again at the end of the term. Greater trait anxiety predicted poorer health at the end of the term when controlling for initial health. In addition, the more dancers wanted to avoid performing worse than others (performance-avoidance goals), the poorer was their physical health at term's end. It is concluded that anxiety and performance-avoidance goals may hinder dancers’ ability to cope with the physical stress associated with a dance career.
Bone Mineral Density and Body Composition of Collegiate Modern Dancers
Authors: Friesen Karlie J. , Rozenek Ralph , Clippinger Karen , Gunter Kathy , Russo Albert C. , Sklar Susan E.
Published: May 2023

This study investigates body composition (BC), bone mineral density (BMD), eating behaviors, and menstrual dysfunction in collegiate modern dancers. Thirty-one female collegiate modern dance majors (D), 18 to 25 years of age, and 30 age-matched controls (C) participated in the study. BC and BMD were measured using dual energy x-ray absorptiometry (DXA). Upper and lower body strength was assessed by chest and leg press one-repetition maximum tests. Participants completed three-day food records, and the diet was analyzed using nutritional software. Menstrual dysfunction (MD) and history of eating disorder (ED) data were collected via questionnaires. BC and BMD variables were analyzed using MANCOVA and frequency of ED and MD by Chi-Square analysis. BMD was greater in D than C at the spine (1.302 ± 0.135 g/cm2vs. 1.245 ± 0.098 g/cm2), and both the right hip (1.163 ± 0.111 g/ cm2vs. 1.099 ± 0.106 g/cm2) and left hip (1.160±0.114 g/cm2vs. 1.101 ±0.104 g/ cm2; p ≤ 0.05). Total body fat percentage was lower in D than C (25.9 ± 4.2% vs. 32.0 ± 5.9%; p ≤ 0.05), and percent of fat distributed in the android region was also lower in D than C (28.0 ± 6.2% vs. 37.6 ± 8.6%; p ≤ 0.05). With regard to diet composition, only percent fat intake was lower in D than C (27.54 ± 6.8% vs. 31.5 ± 7.4%, ≤ 0.05). A greater incidence of ED was reported by D than C (12.9% vs. 0%; ≤ 0.05), as well as a greater incidence of secondary amenorrhea (41.9% vs 13.3%; p ≤ 0.05). No differences were found for incidence of primary amenorrhea, oligomenorrhea, or use of birth control. Strength values were higher in D than C for both chest press (30.1 ± 0.9 kg vs. 28.4 ± 1.0 kg; ≤ 0.05) and leg press (170.7 ± 4.2 kg vs. 163.1 ± 3.9 kg; ≤ 0.05). It is concluded that the dancers in our study had a healthy body weight, yet reported a higher incidence of eating disorders and menstrual dysfunction, than non-dancers. These dancers’ higher BMD may be attributable to the mechanical loading and increased strength associated with practicing modern dance. Further, modern dancers had lower centrally located body fat, which decreases the risk for cardiovascular and metabolic diseases.
Case Studies in Cervicothoracic Spine Function
Authors: Sandow Emily
Published: May 2023

It has been reported that manual therapy directed at the thoracic spine followed by exercise may improve outcomes in patients with mechanical neck pain. At this point, there is little available data on dancers with neck pain, and it is unclear whether this type of treatment is appropriate for restoring the rigorous level of activity required of the dancer. The purpose of this study was to review the evaluation, clinical decision-making process, and treatment of two dancers—one with acute and the other with chronic neck pain—who fell into the classification of patients who might benefit from an intervention to the thoracic spine. The two participants were a musical theater dancer with an acute onset of neck pain and a retired dancer who was an active dance company director with an 11 -year history of chronic neck pain. Both participants went through a standard examination and were treated with mobilizations to the upper thoracic spine followed by therapeutic exercises. In both cases, successful outcomes were achieved immediately after treatment and up to six months after discharge from physical therapy.
Development and Evaluation of an Educational Intervention Program for Pre-professional Adolescent Ballet Dancers
Authors: Doyle-Lucas Ashley F. , Davy Brenda M.
Published: May 2023

The purpose of this investigation was to develop, implement, and evaluate a theoretically based nutritional education intervention through a DVD lecture series (three 30-minute classes) in summer intensive programs for pre-professional, adolescent ballet dancers. Objectives of this intervention program were to increase knowledge of basic sports nutrition principles and the Female Athlete Triad and promote self-efficacy for adopting healthier dietary habits. Dancers ranging from 13 to 18 years old who were attending summer intensive programs affiliated with professional ballet companies were recruited. Group One (n = 231) participated in the nutrition education program, while Group Two the control participants (n = 90) did not. Assessments of the participants’ dietary status consisted of a demographic questionnaire, a Sports Nutrition Knowledge and Behavior Questionnaire, and a Food Frequency Questionnaire. The intervention group was assessed at baseline, immediately post-program, and at six weeks post-program. The control group was assessed at baseline and at six weeks post-baseline. The intervention program was effective at increasing nutrition knowledge, perceived susceptibility to the Female Athlete Triad, and self-efficacy constructs. Improvements in dietary in-take were also observed among intervention group participants. To improve overall health and performance nutrition education should be incorporated into the training regimens of adolescent dancers. This potentially replicable DVD-based program may be an effective, low-cost mechanism for doing that.
The Impact of Mirrors on Body Image and Performance in High and Low Performing Female Ballet Students
Authors: Radell Sally A. , Adame Daniel D. , Cole Steven P. , Blumenkehl Nicole J.
Published: May 2023

This study assesses the effect of mirrors on body image and performance in high and low performing female collegiate ballet students. Twenty-three females enrolled in a beginning ballet class were taught using mirrors, and a second group of 23 beginning females were taught without mirrors. All participants completed the Cash 69-item Body Self-Relations Questionnaire during the first and last class of a 14-week semester. They were videotaped performing in the studio during the fifth and fourteenth weeks. Two ballet teachers independently viewed the videotapes to evaluate the dancers’ rhythmic accuracy, ease and flow of movement, and mastery of steps and alignment, and rated the students’ skill level on a 1-5 scale. For analysis purposes, students whose scores averaged three or higher were categorized as “high performers,” and those who averaged less than three were “low performers.” Two (mirror, non-mirror) by two (high performance, low performance) by two (pre-test, post-test) repeated measures ANOVAs were used to test class differences over the course of the semester. There were significant 3-way interactions for overweight preoccupation (p < 0.01) and body-areas satisfaction (p < 0.05). Low performers increased in overweight preoccupation in the non-mirror class while decreasing in the mirror class. High performers significantly increased in satisfaction for most areas of their body in the non-mirror class, while there were smaller increases for both low and high performers in the mirror class. It is concluded that while use of the mirror has some benefits in training, higher performing dancers feel better about their body image when they do not use the mirror. Lower performers who use the mirror worry less about their weight; those who do not use the mirror worry more. The mirror may provide feedback that helps low performing dancers feel more comfortable with their weight.
The Effect of Sprung (Suspended) Floors on Leg Stiffness during Grand Jeté Landings in Ballet
Authors: Hackney James , Brummel Sara , Jungblut Kara , Edge Carissa
Published: May 2023

This study compared stiffness of the landing leg in ballet dancers performing grand jeté on a sprung floor to leg stiffness during the same movement on a hard floor (wood on concrete). Leg stiffness was calculated as the ratio of vertical ground reaction force (in Newtons) to compression of the lower limb (in meters). Thirteen female dancers were measured for five repetitions each at the point of maximum leg compression while landing grand jeté on both of the surfaces, such that 20 milliseconds of data were represented for each trial. The stiffness of the landing leg at the point of maximum compression was decreased by a mean difference score of 6168.0 N/m ± 11,519.5 N/m on the hard floor compared to the sprung floor. Paired t-test yielded a one-tailed probability of p = 0.038. This effect was seen in 11 of the 13 participants. The finding of increased stiffness of the landing leg in the sprung floor condition suggests that some of the force of landing the leap was absorbed by the surface, and therefore did not need to be absorbed by the landing leg itself. This in turn implies that a sprung dance floor may help to prevent dance-related injuries.
Imaging of Hip Injuries in Dancers
Authors: Chow Alex Hung Lit , Morrison William B.
Published: May 2023

Dancers are quite prone to injuries in the hip region. Imaging plays a key role in evaluation of the pain resulting from such injuries, as proximity of structures and cross-innervation can result in a clinical dilemma regarding the specific injury, and thus origin of the pain generator. Advanced imaging techniques, including MRI, ultrasound, and multidetector CT, are becoming increasingly important in the workup of injuries in athletes, yet radiographs remain an essential component. This article presents a variety of injuries in the hip and groin region that may be seen in dancers and discusses the utility of basic and advanced imaging modalities.
Musculoskeletal Ultrasound Applications in the Hip
Authors: Nazarian Levon N.
Published: May 2023

This article illustrates how ultrasound (US) can be useful in the evaluation of painful hips. For an experienced examiner using high quality equipment, US is the imaging test of choice for tendon abnormalities, hernias, bursitis, and dynamic abnormalities such as extra-articular snapping hip. Ultrasound is also useful in screening for hip effusions and guiding diagnostic and therapeutic interventions. Ultrasound has a complementary role to magnetic resonance imaging (MRI) for labral pathology, although MRI or MR arthrography is preferable for most intraarticular pathologies. It is better tolerated, less expensive, and more readily available than MRI, and as US technology continues to improve, its role in hip imaging should grow.
Upper-Body Muscular Endurance in Female University-Level Modern Dancers
Authors: Ambegaonkar Jatin P. , Caswell Shane V. , Winchester Jason B. , Caswell Amanda A. , Andre Matthew J.
Published: May 2023

Physical demands vary among dance styles, and injury patterns differ accordingly. Modern dance tends to be high in upper-body demands, and university-level female modern dancers are suggested to be at high risk for upper-body injury. Low muscular endurance is a known injury risk factor. Whether modern dancers have different upper-body muscular endurance than non-dancers is unclear. Thus, the purpose of this study was to compare upper-body endurance in female univer-sity-level modern dancers (n = 17) and physically active non-dancers (n = 15), using the modified push-up test. Pearson-correlations examined relationships between anthropometrics and push-ups. Multiple regression analyses were used to determine whether anthropometrics and physical activity could predict push-up scores. One-way ANOVAs compared upper-body endurance (number of pushups) and physical activity between groups (p < 0.05). Except for height (r = -.37), no variables were related to push-ups. Neither anthropometrics nor physical activity were able to predict push-up scores (p = 0.25). Despite dancers being more active/day (3.6 ± 1.9 vs. 0.9 ± 0.4 hrs/day ρ < 0.001), more times per week (5.4 ± 1.2 vs. 4.0 ± 1.8, ρ = 0.02), and having greater overall physical activity volumes (20.4 ± 11.4 vs. 3.3 ± 2.5 hrs/week, ρ < 0.001) than non-dancers, both groups had similar upper-body endurance (22.2 ± 8.6 vs. 19.9 ± 8.2, ρ = 0.44). A probable explanation for this similarity exists in the lack of physical activity beyond dance itself performed by the dancers; our preliminary work suggests that modern dance alone may not produce upper-body muscle endurance gains. Hence, it is suggested that modern dancers should engage in strength and conditioning training programs to enhance upper-body endurance.
Effects of Expertise and Auditory Guidance on Traditional Dance Performance
Authors: Sofianidis George , Hatzitaki Vassilia , McKinley Patricia
Published: May 2023

This study investigated how the dancers level of expertise and the type of auditory guidance provided influence the kinematic profile of the lower limbs during traditional dance performance. Ten experts in traditional Greek dance (age: 25 ± 3.29 years, five males and five females) and eleven novice participants (age: 26.45 ±3.88 years, six males and five females), all Greek natives, performed a series of Greek and Irish dance steps with auditory guidance of the metrics (verbal counting) and the music of the respective dances. An electromagnetic tracking system sampled (at 100 Hz) the angular displacement of the two lower legs about the Mediolateral axis during dance perfor-mance. Segment rotations were analyzed in the time and frequency domain. Expert dancers displayed significantly lower vari-ability of lower leg rotation and stronger interlimb coupling when compared to novice performers. In novice performers, the power of the lower limb angular dis-placement extended to higher frequencies when dance performance was guided by music compared to metrical guidance. The addition of music and the origin of the dance interfered with performance for novices but not experienced dancers. Kinematic analysis of the lower limbs may open a new window for the investigation of learning and auditory guidance effects on dance performance.