bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress Injury of the Talar Dome and Body in a Ballerina
Authors: Shah Selina , Luftman Joseph , Vigil Daniel V.
Published: May 2023

Talar stress injury was diagnosed in a 16-year-old ballerina who frequently danced en pointe, a position in which the subtalar joint is locked with the heel and forefoot in varus position. After completing a 6-week non-weightbearing period as prescribed, the patient wore a removable walker boot for 2 weeks. During this period, she underwent non-weightbearing exercise and symptoms resolved. She avoided prohibited movements for 2 weeks; during the next 6 months, she gradually returned to full dance activity. When last seen at follow-up 4 months later, the patient remained pain-free. During en point dancing, the force of full weightbearing is probably transmitted through the talus and thus predisposes it to stress fracture from repetitive loading.
Comprehensive Surveillance of Dance Injuries a Proposal for Uniform Reporting Guidelines for Professional Companies
Authors: Bronner Shaw , Ojofeitimi Sheyi , Mayers Lester
Published: May 2023

Varying methods of injury definition, data collection and interpretation of findings complicate analysis of results from epidemiological studies of sport and dance injuries. Comparison between studies is therefore difficult. Researchers have suggested adoption of uniform methodology for injury definition and reporting. This paper outlines a suggested comprehensive injury reporting system for professional dance companies.

Components of a comprehensive injury surveillance system include: 1. pre-season screening of intrinsic risk factors, 2. extrinsic risk factor tracking, and 3. injury occurrence reporting system. Dance screens provide healthy baseline data, uncover existing pathology, and help define population characteristics. Extrinsic risk factor tracking includes quantification of exposure to specific environment, equipment, and technique demands. Exposure may be delineated as activity (number of performance, class, and rehearsal events) or time (hours of participation in dance activities) based. These exposure measures are then incorporated into incidence calculations, enabling injury rate comparison between populations.

Standardized injury definitions are proposed to facilitate the comparison of injury rates. We propose defining “injury” as any physical complaint sustained by a dancer resulting from performance, rehearsal, or technique class. Injury is further delineated in the following ways: 1. physical complaint injury, 2. medical injury, 3. time-loss injury, and 4. financial injury. Coding by severity, injury type, location, tissue, activity, and style of dance and choreography is also included. We hope this may ultimately result in uniform injury registration for dancers of all ages and levels. Adoption of a common system should result in improved understanding of injury incidence and risk factors with potential to increase the effectiveness of injury prevention interventions and rehabilitation.
Dancing in Pain: Pain Appraisal and Coping in Dancers
Authors: Anderson Ruth , Hanrahan Stephanie J.
Published: May 2023

This study investigated the relationships between the type of pain experienced (performance pain andinjury pain), the cognitive appraisal of pain and pain coping styles in dancers. Fifty-one professional ballet and contemporary dancers (17 males and 34 females), with the mean age of 25.9 years, completed a general pain questionnaire, the Pain Appraisal Inventory, the Survey of Pain Attitudes Control Subscale, and the Sports Inventory for Pain. Multivariate analyses of variance indicated that both the cognitive appraisal of the pain and pain coping styles did not differ according to the type of pain experienced or the pain severity. However, it was found that dancers with performance pain of either low or high severity were more likely to dance in pain than dancers experiencing injury pain. Multiple regression analyses indicated that the appraisal of pain as threatening was predictive of the use of avoidance and catastrophizing pain coping styles. Overall, results indicated that dancers may not differentiate between performance pain and injury pain, or modify their appraisal and coping strategies according to the characteristics of the pain experienced. The study highlighted an opportunity for increased education for dancers in recognizing the difference between pain considered to be a routine aspect of training and pain which is a signal of serious injury.
Biomechanics of the Foot in Dance: A Literature Review
Authors: Ahonen Jarmo
Published: May 2023

In any form of dance, great strain is placed on the lower extremity and the strong but sensitive foot. A large percentage of injuries to dancers involve the foot and ankle. Understanding the structure, biomechanics, and physics of the lower extremity helps to diagnose and evaluate the mechanics behind these injuries.

The lower extremity function is complicated and needs to be studied carefully to understand its laws and principles. What often happens when injury occurs is that the dancer is not satisfying the natural requirements of movement through the joints. For example, her relevé is causing sickling and unstable foot positions because the forefoot is not strong enough and the leg external rotation and hip joint muscular support are not simultaneous with the heel raise. In the opposite direction, when the dancer is executing plié, the outcome of poor control of a weakened foot is strain on the passive supporting structures, such as the plantar ligaments, joint capsules, and plantar fascia. This leads to faulty bone alignment, increased bone load, and risk of overuse syndromes in various tissues.
The Role of Biomechanics in Understanding Dance Movement: A Review
Authors: Wilson Margaret , Kwon Young-Hoo
Published: May 2023

This review introduces different techniques used in biomechanics that have been used in analyzing dance movement. Biomechanics provides information not only for analysis of motion, but for understanding muscle use, forces acting on the body, issues of motor control, and the interaction between any one body part and the body as a whole. The goal of this review is to highlight the role that biomechanical analysis plays in understanding dance movement, with applications for teaching, skill enhancement, and injury prevention.
Measurement of Turnout in Dance Research: A Critical Review
Authors: Champion Lowry M. , Chatfield Steven J.
Published: May 2023

Turnout measurement procedures, results, and reporting formats vary in dance medicine and science research, making comparisons difficult. It is agreed that turnout results from summative contributions of the hip, knee, lower-leg, and the foot-ankle complex. However, the most frequently reported measurement is hip external rotation, and even this is measured in incompatible ways. No normative data exist for component and summative measures or for different categories of dancers, making screening, clinical assessment, and research problematic. Thus, there is a need to standardize component measurements, develop an inclusive measurement procedure for total turnout, and establish normative data for each measurement and for different categories of dancers. This review evaluates the 24 published articles that have reported original data for turnout assessment in dancers. Results are summarized and displayed for each article. In conclusion, recommendations are made for: use of selected hip external range of motion and tibial version measurements as the most important components of turnout; a procedure for assessing total turnout; adoption of conventions for reporting data in compatible forms; and the development of normative data sets for different categories of dancers.
Assessing Turnout in University Dancers
Authors: Welsh Thomas M. , Rodriguez Mariola , Beare Laura W. , Barton Blythe , Judge Tyressa
Published: May 2023

The purpose of this study was to test practical procedures for assessing total turnout in dancers’ lower extremities. Passive, active and best turnout measurements were taken for 17 first-year dancers in a selective university program, using measurement protocols demonstrated to be reliable. The results revealed considerable variability in the degree of turnout available to individual dancers, and a tendency for many dancers to use less turnout while standing than shown to be available when measured passively while supine on an examination table. Thus, the study indicates an opportunity to improve the use of turnout in dancers, and recommends a set of measurement protocols for assessing this capacity to which many dancers and teachers attribute a good deal of importance.
Health Care Seeking Behavior and Perceptions of the Medical Profession among Pre- and Post-Retirement Age Dutch Dancers
Authors: Air Mamie
Published: May 2023

A cross-sectional, descriptive survey and a medical chart review of 154 pre- and post-retirement age injured Dutch dancers were performed. The purpose was to examine dancers’ health care seeking behavior and perceptions of the medical profession in context of the current health care system in The Netherlands, which includes both universal access and expertise in performing arts medicine. No logistical or perceptual restrictions to health care were reported by the dancers in this study. Only three younger dancers (< 35 years) lacked a primary care physician. No dancer reported monetary or insurance hindrances to acquiring an appointment or fear of going to the doctor. A small percentage of the younger group (18%), but none of the older dancers, reported that they felt the doctor would not understand them (χ2= 2.2, df = 1, p = 0.14). Dancers in both age groups most often sought first treatment from either a physiotherapist (36% to 40%) or a medical doctor (38.8% to 40.8%). When a physician was not consulted first, the primary reason was that dancers had already seen a physiotherapist and thought this treatment was sufficient. Approximately one-third of dancers expected their medical problem to go away on its own.

Dutch dancers were additionally found to have a positive relationship with the medical profession, including high satisfaction and confidence. The majority of dancers were satisfied or very satisfied with their medical treatment prior to presenting to the dance medicine specialist (67% older dancers, 52% younger, χ2= 1.19, df = 1, p = 0.2). Nearly every dancer was satisfied or very satisfied after treatment by the specialist (100% older dancers, 93% younger dancers, χ2= 1.46, df = 1, p = 0.2), and moderately or completely confident of full recovery (80%, each group).

Differences in older and younger dancers’ perceptions and behaviors were nevertheless found. Older dancers were significantly more likely to continue to dance when injured than younger dancers (100% versus 82%, χ2= 5.14, df = 1, p = 0.02), although pain and perceived level of artistic hindrance were similar between the groups at first presentation to a dance medicine clinic (pain: 32.6 versus 34.0 mm, respectively, p = 0.83; artistic hindrance: 49.3 versus 58.0 mm, p = 0.29, respectively). Older dancers were more likely to wait and see for themselves whether an injury would get better by itself (14% versus 4%, χ2= 4.1, df = 1, p = 0.05). Average time to seek treatment from a medical doctor was four times longer among older than younger dancers (8.4 versus 2.1 months, respectively, p = 0.004), and older dancers had less confidence in full recovery at first visit (40% versus 61%, χ2= 3.8, df = 1, p = 0.05).

Thus, the medical system of The Netherlands is one that confers improved health care access and perceptions of the medical profession among dancers, yet there remain areas to be addressed in terms of equalization of health care delivery.
Considerations for Integrating Fitness into Dance Training
Authors: Rafferty Sonia
Published: May 2023

In recent years it has frequently been suggested that dancers may not be sufficiently prepared for the physical demands of dance. The majority of researchers have arrived at the conclusion that there are gaps in the structure of dance training programs that could be filled with the type of physical training that has benefited other elite athletes. This article reviews some recommendations in light of current research for the supplementation of dance training and the inclusion of fitness concepts in traditional dance classes.
Functional Criteria for Assessing Pointe-Readiness
Authors: Richardson Megan , Liederbach Marijeanne , Sandow Emily
Published: May 2023

The most popular criterion cited in the dance literature for advancement to pointe work is attainment of the chronological age of 12 years. However, dancers at this age vary greatly in terms of musculoskeletal maturity and motor skill development. The purpose of this study was to investigate whether objective, functional tests could be used in conjunction with dance teacher expertise to determine pointe-readiness. It was hypothesized that dynamic tests of motor control can better indicate pointe-readiness than chronological age alone or in combination with static musculoskeletal measurements. Thirty-seven pre-pointe students from two professional ballet schools were tested for muscular strength, ankle joint range of motion, single leg standing balance, dynamic alignment, and turning skill. In addition, the participating students’ ballet teachers independently graded each student on her readiness to begin dancing en pointe. Performance on three functional tests (the Airplane test, Sauté test, and Topple test) was closely associated with teacher subjective rating for pointe-readiness. It is concluded that these tests may be more useful for gauging acquisition of the skills required for safe and successful performance than the traditionally accepted indicators of chronological age, years of dance training, and ankle joint range of motion.
Overview of Thigh Injuries in Dance
Authors: Deleget Alison
Published: May 2023

Thigh injuries include musculotendinous strains of the quadriceps, hamstrings, adductors, iliotibial band (ITB), and bony injuries to the shaft of the femur. There is scant information in the literature regarding thigh injuries in dance, which appear to range from 5% to 16% of total injury incidence. Hamstring strains and ITB syndrome are the most commonly reported thigh injuries. Hamstring injuries occur most frequently during slow stretching when the dancer's hip is flexed and knee extended. Uniquely in dancers, adductor injury occurs concurrently with hamstring injuries in approximately one-third of cases. Snapping of the ITB at the lateral hip and knee may result from imbalance of thigh muscle strength and flexibility. To date no quadriceps strain injuries or stress injuries to the shaft of the femur have been reported in the dance medicine literature. As dancers notoriously underestimate time needed to return to dance, it can be suggested that early return to work is a contributing factor to chronic injury. Further research is needed regarding the incidence and nature of injury to the thigh among dancers.
The Demands of a Working Day among Female Professional Ballet Dancers
Authors: Twitchett Emily , Angioi Manuela , Koutedakis Yiannis , Wyon Matthew
Published: May 2023

Professional classical ballet dancers typically face long working days, and many complain of fatigue, particularly as a possible cause of injury. However, little information exists regarding the true physiological demands on dancers. The aim of the present study was therefore to ascertain the daily workload of professional female ballet dancers in terms of work intensity and rest data. Information regarding a single “work day” was obtained from 51 female dancers in one company using a multiple accelerometer. Data were examined for the amount of time spent at work intensities measured in metabolic equivalents (METS)deemed sedentary, low, moderate, and high, and the length of each period at rest. Results indicated significant differences between dancer rankings (corps de ballet, first artist, soloist, and principal) for mean exercise intensity and the percentage of time spent at sedentary intensity (< 3 METS), moderate intensity (3-6 METS) (p < 0.005), and vigorous intensity (6-9 METS) (p < 0.05). The ratios of time spent below 1.5 METS versus time spent above 1.5 METS (“rest” vs. “work”) were also significantly different (p < 0.001) between rankings. When rest periods throughout the working day were analyzed, 90% of dancers were found to spend less than 60 consecutive minutes resting at any one time; for 33.3% of dancers this was less than 20 minutes. Results also revealed significant differences (p < 0.05) between dancer rankings for the greatest amount of rest at any one time during the day. It was concluded that female professional classical ballet dancers’ ranking in their companies should be considered in devising work-rest schedules to help them to avoid fatigue and resultant injuries.
Energetic Efficiency, Menstrual Irregularity, and Bone Mineral Density in Elite Professional Female Ballet Dancers
Authors: Doyle-Lucas Ashley F. , Akers Jeremy D. , Davy Brenda M.
Published: May 2023

Sports that emphasize low body weight for optimal performance, such as ballet, are associated with an increased prevalence of the female athlete triad (FT). Previous research in this area that involves dancers has been limited; the majority of studies have been performed on adolescents training in classical ballet, and not professional adult dancers. The purpose of this study is to compare the physical and behavioral characteristics of female elite ballet dancers to sedentary, recreation-ally active non-dancing controls, with regard to characteristics of the FT and energetic efficiency. Women aged 18 to 35 years were recruited as participants. The dancers (N =15) and non-dancing controls (N =15) were pair-matched via age (dancers: 24.3 ±1.3 years; controls: 23.7 ± 0.9 years), body mass index (dancers: 18.9 ± 0.2; controls: 19.4 ± 0.2 kg/m2), and fat-free mass (dancers: 44.3 ± 0.8; controls: 44.1 ± 0.9 kg). Assessments included habitual dietary intake using 4-day food records, self-reported physical activity, psychometric measures of eating behaviors, health and menstrual history, body composition and bone density (dual energy x-ray absorptiometry), and resting metabolic rate (RMR) assessed by indirect calorimetry. Characteristics of the FT, specifically menstrual irregularities (6 of 15 dancers reported irregular or no menses; 1 of 15 controls reported irregular menses) and low energy availability, were more prevalent in dancers than in pair-matched controls. Despite having a similar fat-free mass (FFM), dancers had a significantly lower absolute RMR (dancers: 1367 ± 27; controls: 1454 ± 34 kcal/d; p ≤ 0.05) and significantly lower RMR relative to FFM (dancers: 30.9 ± 0.6; controls: 33.1 ± 0.8 kcal/kg fat-free mass/d; p ≤ 0.05). Energy intake between dancers (1577 ± 89 kcal/d) and pair-matched controls (2075 ± 163 kcal/d) also differed significantly (p ≤ 0.01). Six of the 15 dancers met the criteria for the FT (including low bone mineral density, menstrual irregularities, and eating pathology accompanied by low energy availability) and, therefore, represent a population of individuals afflicted with this disorder. These findings provide insight as to the metabolic impact of chronic energy restriction, and suggest that alterations in RMR (i.e., energetic efficiency) may be an indicator of low energy availability. Future larger-scale studies are warranted to address this possibility. Interventions aimed at increasing energy availability in elite female ballet dancers may be needed to promote optimal health status.
The Effects of Nutrition, Puberty and Dancing on Bone Density in Adolescent Ballet Dancers
Authors: Burckhardt Peter , Wynn Emma , Krieg Marc-Antoine , Bagutti Carlo , Faouzi Mohamed
Published: May 2023

Ballet dancers have on average a low bone mineral content (BMC), with elevated fracture-risk, low body mass index (BMI) for age (body mass index, kg/m2), low energy intake, and delayed puberty. This study aims at a better understanding of the interactions of these factors, especially with regard to nutrition. During a competition for pre-professional dancers we examined 127 female participants (60 Asians, 67 Caucasians). They averaged 16.7 years of age, started dancing at 5.8 years, and danced 22 hours/week. Assessments were made for BMI, BMC (DXA), and bone mineral apparent density (BMAD) at the lumbar spine and femoral neck, pubertal stage (Tanner score), and nutritional status (EAT-40 questionnaire and a qualitative three-day dietary record). BMI for age was found to be normal in only 42.5% of the dancers, while 15.7% had a more or less severe degree of thinness (12.6% Grade2 and 3.1% Grade 3 thinness). Menarche was late (13.9 years, range 11 to 16.8 years). Food intake, evaluated by number of consumed food portions, was below the recommendations for a normally active population in all food groups except animal proteins, where the intake was more than twice the recommended amount. In this population, with low BMI and intense exercise, BMC was low and associated with nutritional factors; dairy products had a positive and non-dairy proteins a negative influence. A positive correlation between BMAD and years since menarche confirmed the importance of exposure to estrogens and the negative impact of delayed puberty. Because of this and the probable negative influence of a high intake of non-dairy proteins, such as meat, fish, and eggs, and the positive association with a high dairy intake, ballet schools should promote balanced diets and normal weight and should recognize and help dancers avoid eating disorders and delayed puberty caused by extensive dancing and inadequate nutrition.
Immediate Effect of Static and Proprioceptive Neuromuscular Facilitation Stretching on Hip Adductor Flexibility in Female Ballet Dancers
Authors: Rubini Ercole C. , Souza Andréa C. , Mello Mônica L. , Bacurau Reury F. P. , Cabrai Leonardo R , Farinatti Paulo T. V.
Published: May 2023

The aim of the present study was to investigate the immediate effects of static and proprioceptive neuromuscular facilitation (PNF) stretching on the flexibility of hip adductors in female ballet dancers. Forty-five subjects (age: 28.5 ± 8.0 years; minimum two years of ballet training) were randomly assigned to three groups: PNF (contract-release technique), Static, and Control. Subjects in the PNF and Static groups performed four sets of 30 second stretching with an interval of 30 seconds between sets. The control group stayed at rest for the same time spent by the PNF and Static groups during the stretching sessions. Maximal range of motion was measured before and immediately after the experimental and control protocols in all groups. The results indicated significant differences between pre- and post-stretching flexibility in both PNF and Static groups (p < 0.0001; effect size = 0.24 and 0.39, respectively), whereas no change was identified in the Control group (p = 0.265). However, no differences in post-exercise flexibility were found between PNF and Static groups (p = 0.235). It is concluded that static and PNF stretching methods provoked similar post-exercise acute effects on the maximal range of motion of hip adductors in highly flexible female ballet dancers.
Effects of Kinesthetic versus Visual Imagery Practice on Two Technical Dance Movements
Authors: Coker Girón Elizabeth , Mclsaac Tara , Nilsen Dawn
Published: May 2023

Motor imagery is a type of mental practice that involves imagining the body performing a movement in the absence of motor output. Dance training traditionally incorporates mental practice techniques, but quantitative effects of motor imagery on the performance of dance movements are largely unknown. This pilot study compared the effects of two different imagery modalities, external visual imagery and kinesthetic imagery, on pelvis and hip kinematics during two technical dance movements, plié and sauté. Each of three female dance students (mean age = 19.7 years, mean years of training = 10.7) was assigned to use a type of imagery practice: visual imagery, kinesthetic imagery, or no imagery. Effects of motor imagery on peak external hip rotation varied by both modality and task. Kinesthetic imagery increased peak external hip rotation for pliés, while visual imagery increased peak external hip rotation for sautés. Findings suggest that the success of motor imagery in improving performance may be task-specific. Dancers may benefit from matching imagery modality to technical tasks in order to improve alignment and thereby avoid chronic injury.
Stress Fracture of the Second Metatarsal: A Case Report
Authors: Molnar Marika
Published: May 2023

A case of a 17-year-old female ballet student who presented to physical therapy with complaints of pain in her left forefoot is described. She exhibited a stress fracture of the second metatarsal, which was confirmed by a bone scan. The patient's history of an irregular menstral cycle, low weight, the emotional stress and physical demands of her training combined with the results of a biomechanical evaluation provide a classic example of the etiology of this injury in female ballet dancers.
Jump Ability in Novice Ballet Dancers before and after Training
Authors: Poggini Luana , Losasso Stefania , Cerreto Manuela , Cesari Lucia
Published: May 2023

To investigate the jump ability in a group of young dancers, 61 adolescent classical ballet students were analyzed using a force-plate instrument. Each student was evaluated for the rising of the gravity center and the flight time while performing two types of jumps: one from a static position, the other with a preliminary counter-movement. By the comparison of our data with the results of the same test in other athletes, we tried to identify the most specific characteristics of classical ballet training that can have an influence on the height of the vertical jump. The correlation between the height of the jump and the ability of the subjects to maintain a correct en dehors position was also studied, pointing out, finally, the presence of a very common technical error — the double heel strike. Additionally, during the course of the study the subjects were exposed to a physiotechnique program designed to train them in the proper classical ballet technique. The results of this study indicate that this exercise was useful in helping these dancers perform higher jumps in a more technically correct manner.
Spondylolysis in Ballet Dancers
Authors: Seitsalo Seppo , Antila Heikki , Karrinaho Timo , Riihimäki Hilkka , Schlenzka Dietrich , Österman Kalevi , Ahonen Jarmo
Published: May 2023

This study of the incidence of spondylolysis in dancers consisted of 65 subjects who were ballet dancers with the Finnish National Ballet. Radiographs of the spine from 60 (25 male, 35 female) dancers were available for analysis. A questionnaire concerning the history and presence of symptoms of low back was completed by 50 dancers. The mean age at the time of radiography was 24 (16–36) years, and at the time of evaluation of the symptoms 28 (21–43) years. Nineteen dancers out of 60 (32%) had spondylolysis, 15 with and 4 without spon dylolisthesis. This frequency is five times higher than found in the Finnish population. This strongly supports the mechanical etiology involved in the development of spondylolysis. Frequent loa ding (beginning in childhood) of the spine (axial, rotational, and especially in hyperextension) are typical for ballet (arabesque, lifting, and so forth). Conversely, back pain symptoms during a ballet career were not clearly associated with the presence of spondylolysis or spondylolisthesis. It, therefore, seems to be unjustified to advise a ballet dancer with such a defect to discontinue his or her career.
The Relationship between Eccentric and Concentric Measures of Ankle Strength and Functional Equinus in Classical Dancers
Authors: Liederbach Marijeanne , Hiebert Rudi
Published: May 2023

Classically trained dancers possess a supernormal range of motion in ankle plantar flexion with a reciprocally diminished range of motion in ankle dorsiflexion. Restricted joint motion is considered homologous with diminished strength in muscle groups associated with the lost motion and is associated with compensatory hypermobility in neighboring joints. The purpose of this study was to measure clinical and functional ranges of ankle motion and to assess peak torque values for ankle plantar flexion and dorsiflexion collected both eccentrically and concentrically. Twelve professional, classical dancers (6 males, 6 females) were measured goniometrically for ankle range of motion using three different positioning techniques and for isokinetic peak torques of ankle plantar flexion (PF) and dorsiflexion (DF) at two different joint angles and two different speeds. Measured by traditional goniometric techniques, ankle dorsiflexion was limited relative to published norms and significantly lower than measures taken when the dancer assumed a functional testing position. A relationship of moderate strength between dorsiflexion range and peak torque values was obtained, although it did not meet our criterion for significance. No significant differences were seen in either gender between concentric and eccentric measures of ankle strength for any of the testing conditions. The equality of concentric and eccentric measures may reflect a training effect resulting from regularly practiced concentric relevé activities or may be a result of limitations in the laboratory setting.
The Effects of Classical Ballet Training on the Lumbar Region
Authors: Livanelioglu Ayse , Otman Saadet , Yakut Yavuz , Uygur Fatma
Published: May 2023

This study was carried out to determine the extent of the adaptive changes in the lumbar region of young ballet dancers when compared to their sedentary peers. Forty female (age: 15.28 ± 2.02 years) ballet dancers were evaluated for muscle strength, lumbar mobility, muscle tightness, spinal deviation, and depth of lordosis. Measurements were compared with those of 40 healthy female (age 15.35 ± 2.33 years) non-dancers. No difference was found in muscle strength between the two groups ( p < 0.05). Lumbar mobility was higher and the muscle tightness in the hamstring muscles was lower in the dance subjects. The difference was statistically significant ( p < 0.05). Deviation and depth of lumbar lordosis was found to be significantly lower in the dance subjects ( p < 0.05). It can be concluded that training in classical ballet has various effects on the musculoskeletal structures of the lumbar region and these effects should be taken into consideration for the prevention of overuse injuries.
The Effects of Participation in Dance Technique Classes on Student Performance on a Spatial Kinesthetic Awareness Test
Authors: Minton Sandra , McGill Karen
Published: May 2023

This study sought to assess the performance of university undergraduates (n = 150) on the Spatial Kinesthetic Awareness Test (SKAT) using a pretest and posttest format. All subjects were enrolled in jazz or modern dance classes at the beginning or intermediate level. Analysis of student performance was done from videotapes. Students showed a significant improvement ( p < 0.05) in overall performance on the SKAT in four of the nine classes tested.
Injuries, Amenorrhea and Osteoporosis in Active Females
Authors: Myszkewycz Lynne , Koutedakis Yiannis
Published: May 2023

Menstrual abnormalities, and the associated osteoporotic disorders, are becoming increasingly common in females who are engaged in heavy training and exercise schedules. Such conditions may lead to a significant decrease in vertebral bone density, and an increase in injuries to the hip, ankle, foot, and wrist. In general, fracture frequency increases as bone mineral density decreases. Many researchers have linked various factors, including nutrition, low body weight, low caloric intake, hormonal status, and psychological and physiological stress, to the cause of amenorrhea. However, controversy still exists about the actual etiology of the disorder, although it is most probably multi-factorial. Whatever the actual etiology, the frequency of bone-related injuries has increased dramatically over the last few decades along with the increased popularity of dance and sports and the increased demands placed upon both female dancers and athletes.
Dancer Disordered Eating
Authors: Culnane Catherine , Deutsch Donna
Published: May 2023

The purpose of this study was to assess nutritional status; to examine the prevalence of disordered eating behavior; and to determine if a relationship existed between nutritional status and disordered eating behavior among female dancers. Twenty-one female dance majors from the undergraduate dance department at a major northeastern university participated in the survey which included: three-day food and activity records from the DINE U.S. nutritional program; EAT-26 eating attitudes assessment; and University Dancer Profile (UDP), an instrument designed by the principal researcher.

On the EAT-26, 4 out of 21 subjects (19%) scored in eating disorder symptomatic range. The group means for the DINE U.S. nutritional subscales were below recommended levels: caloric intake, 59% (SD = 17.6); protein, 75% (SD = 20.9); calcium, 48% (SD = 19.8); iron, 63% (SD = 27.8); and phosphorus, 80% (SD = 24.7). A Fisher Exact Test for Significance in a 2 x 2 Contingency Table confirmed no significant relationship between disordered eating behavior and nutritional status. On the UDP, 76% of the sample scored in the Body Dissatisfaction range.

We can conclude, therefore, that the sample population has normal eating attitudes, yet is preoccupied with body weight and shape, and that the subjects restrict their caloric intake. The results of this study indicate that the female dance population may be at risk for developing subclinical eating disorders within the dance subculture, or Dancer Disordered Eating.
A 10-Week Training Study Comparing Resistaball® and Traditional Trunk Training
Authors: Stanforth Dixie , Stanforth Philip R. , Hahn Stephanie R. , Phillips Allison
Published: May 2023

The Resistaball® is an inflatable plastic ball designed for “stability training” of the trunk. The purpose of this study was to compare traditional floor work (T) with Resistaball® exercise (R) in training the abdominal and back extensor muscles. Fifty-five female subjects ranging in age from 20 to 40 years participated in the study. The T group (15 subjects) and R group (20 subjects) participated in pretesting, 10-weeks of exercise, and post-testing; while the non-exercising controls (C group; 20 subjects) participated only in pretesting and post-testing. The exercise program for both the T and R groups consisted of crunches, oblique twists, and back extensions on the floor (T) or ball (R). Subjects performed no other abdominal or back training over the 10-week period. The pretest and post-test consisted of double leg lowering (DLL), trunk flexion (AB), and back extension (BE). For DLL, each subject was supine with hips flexed at 90° and was asked to slowly lower both legs. The point at which there was any movement at the lower back or pelvis was measured using a Universal goniometer. The AB and BE tests were conducted on Cybex® machines. Subjects self-selected a resistance they determined to be “somewhat hard to hard” and flexed or extended repeatedly against that resistance to volitional failure or until they were unable to perform the movement correctly. During post-testing, subjects completed the AB and BE tests to volitional failure using the pretest resistance. A one-way ANOVA with paired t-tests and General Linear Model were used to analyze the data for initial differences, net gain, percent gain, and group factor. For DLL, those in the R group using the Resistaball® improved significantly more than either those who used traditional floor work or controls ( p < 0.05). For AB, there was no significant difference between any of the groups ( p > 0.05). For BE, both those who used Resistaball® training and those who used traditional floor work improved significantly more than controls ( p < 0.05), but there was no difference between the R and T groups ( p > 0.05). In conclusion, exercise training with the Resistaball® was comparable to traditional floor work for training the abdominal and back muscles and may be of greater benefit for functional activities that require spinal and pelvic stabilization.
Stress Fractures in Ballet
Authors: Lundon Katie , Melcher Lindsay , Bray Krista
Published: May 2023

Stress fractures are common in young ballet dancers, however the roles of the individual contributing factors are unclear. The goal of this study was to review the etiopathophysiology of stress fractures (affected sites, predisposing factors, clinical identification, and diagnostic tests) with a consideration of lower kinetic chain biomechanics in a population of young females involved in intensive ballet training. A retrospective review of 1,023 medical charts from students enrolled at the National Ballet School, Toronto, Canada over the past 25 years was performed to identify the site, mechanism, and incidence of stress fracture. Stress fractures were reported in 31 (3%) cases. The second metatarsal, fibula, tibia, and lumbar spine were identified as areas vulnerable to stress fracture in this population, each associated with a characteristic biomechanical pattern of activity. In addition, 52% of all stress fractures documented were associated with other orthopaedic conditions such as hallux valgus, pronated feet, a longer second metatarsal, genu valgum, hyper-extension of the knees, and scoliosis. Young, skeletally immature females involved in intensive ballet training are especially susceptible to stress fracture development. A combination of repetitive loading and stressful lower kinetic chain activities, in addition to the influence of co-existing predisposing factors in this population, such as amenorrhea and decreased nutritional intake, all contribute to this condition. Evaluation of the unique repetitive movements inherent to this population will serve to direct preventative measures and provide appropriate rehabilitative strategies for stress fracture management.
Storytelling, sociology and sexuality: Ken Plummer’s humanist narrative analysis
Authors: Jackson Stevi , Scott Sue
Published: May 2023

We are approaching Ken Plummer’s work from the standpoint of our shared history in interactionist sociologies of sexuality and interest in sexual storytelling. Plummer was truly a trailblazer in the study of sexuality. He was one of the first in the UK to approach sexuality from a distinctively sociological and interactionist perspective which, while innovative, was out of tune with the Marxist and psychoanalytical mood of the time and was later further sidelined by more fashionable poststructuralist and postmodern theorising. Yet, Plummer’s approach was incredibly productive in focussing attention on sexuality as always socially situated and relational – themes which were carried into his influential work on narrative and storytelling. Also significant was his longstanding commitment to a radical critical humanism, even at times when humanism was very much out of favour. These are the aspects of Plummer’s work that we will take up in this evaluation, arguing for its continuing value as a flexible and open approach with a potential applicability beyond ‘western’ contexts in extending our understanding of the variability and diversity of human sexuality as always situated in specific historical, social, cultural, political and relational settings.
Twitter activity surrounding the Finnish green party's cannabis legalisation proposal: A mixed-methods analysis
Authors: Unlu Ali , Hupli Aleksi
Published: May 2023

Background: In September 2021, a Finnish political party, the Greens, voted to include cannabis policy reform in their party programme, which would legalise the use, possession, manufacture and sale of cannabis. A rapid public discussion has emerged on different social media platforms, including Twitter. Methods: We downloaded 10 days of Twitter data and prepared it for further text analysis, including sentiment, topic modelling and thematic content analysis. Results: Before the proposal, the average daily number of tweets was approximately 140. However, during the week of the proposal, there was a significant increase in tweet volume, reaching a peak of 6,600 tweets on a single day, with a daily average of over 2,700 tweets. Sentiment analysis showed that during the public discussion, the sentiment scores of the tweets were more likely to be positive. Through topic modelling analysis, we obtained the weight of the topic for each tweet, which enabled us to identify the most representative tweets in our corpus. To narrow the sample size for content analysis, we selected tweets that had a topic percentage distribution of over 0.95 (N=188) for closer thematic content analysis. Several positive and negative themes emerged, which were then categorised under broader topics. Similar themes were identified in the most retweeted, liked and commented tweets, which came mainly from known public figures, including politicians, health experts and NGO leaders. Conclusion: Our results show that the discussion was not limited to cannabis legalisation, but instead covered a variety of topics related to drug policy.
Economic inequality and the long-term future
Authors: Schmidt Andreas T. , Juijn Daan
Published: May 2023

Why, if at all, should we object to economic inequality? Some central arguments – the argument from decreasing marginal utility for example – invoke instrumental reasons and object to inequality because of its effects. Such instrumental arguments, however, often concern only the static effects of inequality and neglect its intertemporal consequences. In this article, we address this striking gap and investigate income inequality's intertemporal consequences, including its potential effects on humanity's (very) long-term future. Following recent arguments around future generations and so-called longtermism, those effects might arguably matter more than inequality's short-term consequences. We assess whether we have instrumental reason to reduce economic inequality based on its intertemporal effects in the short, medium, and the very long term. We find a good short and medium-term instrumental case for lower economic inequality. We then argue, somewhat speculatively, that we have instrumental reasons for inequality reduction from a longtermist perspective too, primarily because greater inequality could increase existential risk. We thus have instrumental reasons to reduce inequality, regardless of which time-horizon we take. We then argue that from most consequentialist perspectives, this pro tanto reason also gives us all-things-considered reason. And even across most non-consequentialist views in philosophy, this argument gives us either an all-things-considered or at least weighty pro tanto reason against inequality.
Self-selection or indoctrination in the study of (standard) economics: A systematic literature review
Authors: Miragaya-Casillas Cristina , Aguayo-Estremera Raimundo , Ruiz-Villaverde Alberto
Published: May 2023

Considerable academic debate exists as to whether students with a background in economics exhibit distinct behavioural patterns that set them apart from students in other academic disciplines. Primarily, the debate concerns whether students who fit the stereotype of the economist choose to study economics (the self-selection hypothesis) or whether economics students develop these behavioural patterns in the course of their university studies (the indoctrination hypothesis). We conducted a systematic literature review that examines both hypotheses. According to the literature reviewed, the majority of researchers find the self-selection hypothesis to be the best supported. However, findings remain inconclusive due to several methodological limitations. In spite of that, this study should facilitate a deeper understanding of what causes behavioural changes in economics students and what exactly these behavioural differences are, among other relevant hypotheses.
Digital learning and public policy in schools: A transformative paradigm for a changing world
Authors: Llorent-Vaquero Mercedes , De Pablos-Pons Juan , Velez Irma
Published: May 2023

This study explores models of digital learning in public educational institutions, focusing on good practices aimed at bringing about instrumental and methodological change, and encouraging the adoption of new values and greater social justice. It identifies challenges and opportunities to propose a dynamic model of public policy on digital education. Eighteen public educational institutions associated with good digital practices in Andalusia (Spain) participated in the study. Using a descriptive method with a survey design, three questionnaires were administered at the institutions. The results confirm the importance of collective practice in encouraging the introduction of digital technologies in educational institutions. The conclusions show that a participatory culture and innovative teaching initiatives can facilitate the digital integration, on which the proposed policy model is based. The study proposes a policy model based on how participatory culture and innovative teaching initiatives can facilitate digital integration in schools. This dynamic, reflexive policy model proposed can be adapted to emerging social changes and used by policymakers, management staff and teachers in primary and secondary education.
PLU1 Promotes the Proliferation and Migration of Glioma Cells and Regulates Metabolism
Authors: Dong Wentao , Wang Lude , Pan Yi , Tu Qi , He Ting , Zhou Tian , Yuan Jianlie , Tong Minfeng
Published: May 2023

Objectives

PLU1 is upregulated in many cancers, including breast, mammary, colorectal, and hepatocellular carcinoma. However, little is known about the potential metabolic mechanisms of PLU1 in glioma progression. Therefore, we investigated the relationship between PLU1 and glioma development.

Methods

We analyzed the relationship between PLU1 expression and World Health Organization (WHO) grade using clinical databases and verified the role of PLU1 in glioma development using transcriptome sequencing, Western blotting, Cell Counting Kit 8, colony formation, and wound healing assays. The relationship between PLU1 and glioma glucose metabolism was also initially explored by changing the concentration of glucose in the culture medium and was validated by metabolomics and energy metabolism.

Result

PLU1 expression was closely related to WHO grade and was significantly elevated in tumor tissues compared to nontumor tissues. Knockdown or inhibition of PLU1 inhibits proliferation and migration of glioma cells. In addition, we found that PLU1 expression was closely associated with glioma metabolism by transcriptomic, metabolomic, and energy-related molecular analyses and correlated with glucose metabolism. We also found that glucose concentration affects PLU1 expression, and that PLU1 expression affects intracellular glucose levels.

Conclusion

PLU1 is a novel regulator of metabolic reprograming and a novel strategy for the treatment of glioma.