bluuebunny/crossref_metadata_2025 huggingface dataset:
An unusual case of checkpoint-inhibitor-induced pleuropericarditis
Authors: Suarez Zoilo K , Finke Ana C , Hospedales Emilio , Perez Ernesto , Sharifzadeh Arya , Foster Jennifer , Ferris Allison
Published: May 2023

Introduction

Pembrolizumab is an immune checkpoint inhibitor that promotes effector T-cell functions on malignant cells by binding to programmed cell death protein 1 (PD-1). Pembrolizumab is well tolerated in most cases with an adverse event profile consisting mainly of pruritus, fatigue, and anorexia. Cardiotoxicity comprises 1% of the total adverse events.

Case report

We present a case of a 64-year-old female with non-small cell lung cancer (NSCLC) who developed pleuropericarditis following pembrolizumab therapy.

Management & outcome

The patient was successfully managed with colchicine, furosemide, and timely initiation of methylprednisolone with the improvement of her symptoms. The decision to discontinue pembrolizumab was made, and six months after this intervention, the patient has remained asymptomatic.

Discussion

Clinicians should recognize these potential immune-mediated adverse effects to provide effective and timely management and optimize patient care.
Correlation Between Attention Deficit Hyperactivity Disorder, Internet Gaming Disorder or Gaming Disorder
Authors: Hong Ji Sun , Bae Sujin , Starcervic Vladan , Han Doug Hyun
Published: May 2023

Objective:

Individuals with internet gaming disorder (IGD) or gaming disorder (GD) had a higher prevalence of ADHD than individuals without IGD or GD. The overpathologizing of excessive gaming behaviors may be associated with the functional impairment due to ADHD in individuals with GD.

Methods:

The present study was designed to compare the gaming patterns, accompanying psychopathology, and co-occurring psychiatric disorders, especially ADHD, between clinical and general gamer samples (17–29 years old).

Results:

Out of the nine IGD criteria, the item “functional impairment” had low diagnostic accuracy in participants with IGD or GD. The IGD (GD) group had a higher prevalence of ADHD compared to the general gamer group. Conversely, there was a higher prevalence of IGD (GD) in the ADHD group compared to the non-ADHD group.

Discussion:

The possibility of ADHD should be considered when IGD or GD is diagnosed in patients with problematic Internet gaming.
Management of Injuries in the Young Dancer
Authors: Luke Anthony , Micheli Lyle J.
Published: May 2023

Individuals involved in the care of the young dancer must understand the etio-logic effects of growth, flexibility, and anatomical alignment on injuries. This article presents an approach to injuries in young dancers and discusses some specific injuries, particularly involving the lower extremities and the spine. Aspects of injury assessment and prevention include attention to each dancer's specific anatomy, proper technique, careful progression of skills, and monitoring the volume and intensity of dance training. Management of the dancer begins with identifying the specific anatomic diagnosis. It is important to be familiar with the demands of dance and the patterns of pain commonly associated with specific injuries. This knowledge helps differentiate between injuries that may be treated non-operatively from those that require further investigations and interventions.
Dance Injuries in the Older Dancer
Authors: Rietveld Boni
Published: May 2023

In a previous article it was shown that the most common injuries in older dancers concern the foot and the knee: hallux rigidus, hallux valgus, and patellofemo-ral osteoarthritis. It is demonstrated how these injuries are related to compensation of insufficient turnout of the hips. Suggestions are made for prevention, both in older and younger dancers, by taking advantage of the experience and artistic qualities of aging dancers and teachers.
Dance Physical Therapy for the Leg and Foot Plantar Fasciitis and Achilles Tendinopathy
Authors: Grossman Gayanne , Wilmerding Virginia
Published: May 2023

In dance, great emphasis is placed on achieving maximal turnout from the hips. The ideal illusion of “perfect” turnout, 90° of external rotation in each hip, is rarely attained yet is regularly achieved with some knee and foot involvement. The practice of working beyond the physical limitations of the body gives rise, in part, to compensatory mechanisms or malalignment of the leg, foot, and ankle complex. Forced or poorly controlled turn out may promote abnormal or excessive pronation. Physical limitations that impair full usage of turn out and the subsequent compensatory mechanisms will be considered. Abnormal or excessive pronation is discussed as one of several etiologies in the development of leg, foot, and ankle injuries in dancers. Further, using plantar fasciitis and Achilles tendinopathy as examples, evaluation and effective rehabilitation strategies are described. Rehabilitation programs for dancers need to be carefully designed to normalize function and promote compliance. Therefore, the treatment programs described for dancers combine traditional rehabilitation with the correction of maladaptive techniques and specific information regarding modifications to the dance regimen during the healing process.
The Role of the Flexor Hallucis Longus and Peroneus Longus in the Stabilization of the Ballet Foot
Authors: Femino John E. , Trepman Elly , Chisholm Kathleen , Razzano Lynn
Published: May 2023

The importance of the flexor hallucis longus (FHL) and peroneus longus tendons in the stabilization of the subtalar joint and the longitudinal arch of the foot was demonstrated in 8 fresh-frozen human cadaver foot and ankle specimens. Dissection of the foot was done to transect stabilizing structures including joint capsule and periarticular ligaments of the medial side of the subtalar, talonavicular, navicular-first cuneiform, and first metatarsocuneiform joints; the subtalar ligaments in the sinus tarsi and the lateral capsule of the middle subtalar facet were also transected. The FHL and peroneus longus tendons were isolated and the specimen fixed to a frame. Without any tension on the FHL and peroneus longus tendons, the foot was supple and unstable. With tension applied to the FHL tendon alone, the bony arch of the foot became rigid, with inversion of the subtalar joint, rising of the longitudinal arch, plantar flexion of the forefoot, and slight adduction of the forefoot. With tension applied to the peroneus longus tendon alone, the bony arch of the foot became rigid, with eversion of the subtalar joint, rising of the longitudinal arch, plantar flexion of the forefoot, and abduction of the forefoot. With tension applied to both the FHL and peroneus longus tendons synchronously, the bony arch of the foot rose and became rigid, with plantar flexion and neutral abduction-adduction position of the forefoot. When additional tension was applied to the peroneus longus, the rigid foot assumed a locked position in mild hindfoot eversion and forefoot abduction. These qualitative observations are consistent with the hypothesis that the FHL and peroneus longus are important stabilizers of the foot in dance (demi-pointe and pointe) and soccer (kick), and may provide an explanation for injury of these tendons with these activities.
Internal Rotation Knee Injury during Ballroom Dance
Authors: Tsien Christine L. , Trepman Elly
Published: May 2023

Dance injuries associated with internal rotation of the leg are unusual and the injuries observed in ballet, modern, and aerobic dance are often associated with the externally rotated (turned out) or neutral (parallel) positions. This report presents a case of an international-style ballroom dancer who sustained a strain to the popliteus tendon without lateral meniscus tear during execution of the syncopated spin, a dance figure involving internal rotation of the leg. Tansient locking of the knee occurred. Pain was located at the posterolateral knee. Examination showed posterolateral joint line tenderness and pain with active external rotation of the flexed knee. Magnetic resonance imaging (MRI) showed effusion around the popliteus tendon. The patient recovered with activity limitation over several weeks. The case demonstrates that ballroom dance activity may result in an internal rotation injury to the knee, an injury that is uncommon in other dance forms.
And the Dance Goes On: Psychological Impact of Injury
Authors: Mainwaring Lynda M. , Krasnow Donna , Kerr Gretchen
Published: May 2023

This review provides a glimpse into the dancers psychological reaction to physical injury. Based on the current evidence, dancers’ reactions to injury involve initial negative affects that may become more positive as the injury heals. Dancers with chronic or overuse injuries are more likely to ignore the injury, sometimes to the point of more severe damage and psychological distress. There is evidence that the impact of injury may vary across different types of injury (acute, chronic, overuse, recurrent), individual differences in personality, levels of knowledge and available information about injury and recovery, and styles of coping and social support. Dancers continue to dance with injury, pain and discomfort, perhaps to avoid the “disruption of self” that emanates from injury, and perhaps because of the embedded subculture in dance that embraces injury, pain, and tolerance. Some implications of these findings for future research, teaching, and clinical practice are discussed.
Disordered Eating in High School Dance Students: Some Practical Considerations
Authors: Robson Bonnie E.
Published: May 2023

For a quarter of a century performing arts medicine personnel have been aware of the elevated risk of eating disorders in preprofessional high school dance students. This article reviews the etiological considerations related to this trend and how they affect the prevention and management of eating disorders. Are the students in question making a considered response to society's demand for a lean appearance, or do they represent a sub-population that is suffering from clinical disorders (the pathologic results of dieting behaviors, self-image problems, social difficulties, physical injuries, and so forth)? Recent school-based programs have shown encouraging results in reducing incidence. On the basis of what those programs have taught us, practical recommendations for the management of existing disorders are presented, from a psychiatric perspective.
Career Transitions in Professional Dancers
Authors: Greben Stanley E.
Published: May 2023

The psychiatrist-author summarizes his experience with 160 dancer-clients within the context of various career transitions: e.g., the ballet school student who graduates and moves into a ballet company; the dancer whose career is threatened by injury; the otherwise untrained performer facing retirement at a young age. Some psychological aspects of dance careers and of career transitions are considered, as is the potential role of psychotherapy in mediating their interrelationships. Finally, the career transitions of each of four dancers are presented to illustrate their personal reactions to the experience.
College Programs for Professional Ballet Dancers: The Impact on Career Transition
Authors: Hamilton Linda H. , Bristow Edward , Byars Michael J.
Published: May 2023

Preparing dancers for the transition to a new career after their performance years are over is a challenge. Lack of education experience outside of dance can put dancers at a distinct disadvantage in today's competitive workforce. This study evaluates the impact of Fordham University's program designed to meet the academic needs of professional dancers. Of 66 dancers who had attended the Fordham program since 1988, 39 completed a questionnaire requesting information about their work and college experience. The findings revealed several factors that influenced these dancers to attend college, including geographical location, tuition reductions, and scheduling adjustments. Financial awards from Dance On, a non-profit organization, also played a role, particularly in the younger performers. These results suggest that Fordham's program, in conjunction with Dance On, may serve as a model for enrolling professional dancers in college.
Incidence of Achilles Tendon Injuries in Competitive Highland Dancers
Authors: Young Aileen , Paul Lorna
Published: May 2023

Highland dancing has many similarities to ballet. Anecdotally, highland dancers are prone to sustaining injuries to their Achilles tendon (AT), but very few studies have investigated these injuries. The aim of the study was to examine the incidence and treatment of Achilles tendon injuries in competitive highland dancers. Seventy questionnaires were distributed at two major highland dance competitions in Scotland. The questions related to number of injuries to the AT, history and treatment of the injuries, training techniques, and competition habits. Thirty-eight questionnaires were returned and 33 were suitable for analysis. Ten of the dancers (30%) had experienced injuries to their AT and nine of the ten dancers had consulted a physical therapist. There were no statistical differences between injured and non-injured dancers in the number of hours practiced, or the type of floor used for practice. The injured dancers, however, were significantly older and had been dancing for a greater number of years compared to the non-injured dancers (p > 0.05). Health care practitioners, in particular physical therapists, have a major role in the prevention and treatment of AT injuries in highland dancers, especially regarding “older” dancers and those who have been dancing for many years.
Effect of Anterior Cruciate Ligament Reconstruction on the Passé Movement in Elite Dancers
Authors: Bronner Shaw , Kaminski Terry R. , Gordon Andrew M.
Published: May 2023

Semitendinosus-gracilis (STG) and patella-tendon-bone (PTB) are frequently selected grafts for anterior cruciate ligament (ACL) reconstruction in dancers. While STG and PTB grafts appear to be similar in restoring acceptable mechanical joint stability, it is not known whether there are alterations in the kinematics of dance movements following these procedures. The present study examined two-dimensional kinematics of trunk-lower extremity coordination in 18 adult professional dancers: six dancers with STG, six with PTB graft ACL reconstruction, and six healthy controls. All dancers with ACL reconstruction had returned to full dancing and performance with no visible asymmetries in their dancing. We examined whether temporal organization and peak velocity of the gesture limb differed between dancers with STG and PTB graft reconstruction and controls when performing the passé. Hip and knee peak angular velocities were slower on the involved limb of STG and PTB dancers compared to controls. Adaptations were seen bilaterally in delayed movement times, shorter deceleration times, and greater number of movement units in the ACL reconstruction groups. These findings suggest that injury to a single joint can affect kinematics throughout the involved and uninvolved lower extremities. The altered movement patterns found in dancers with both types of ACL reconstruction suggest that their control of complex movements may be adaptive in nature.
Using the Test of Attentional and Interpersonal Style (TAIS) for Profiling and Counseling Dancers
Authors: Solomon Ruth , Solomon John , Micheli Lyle J. , Saunders John J. , Zurakowski David
Published: May 2023

In a previous report the authors used the Test of Attentional and Interpersonal Style (TAIS), a personality profiling instrument that is well established in the world of sport, for the first time with dancers. Two groups of subjects, one composed of elite professional ballet dancers (n = 41), the other of conservatory dance majors (n = 42), were compared in the interest of exploring the feasibility of developing a psychological profile of the dancer's personality. The present study expands the subject base originally available to encompass 83 professionals and 110 students. The results achieved were virtually identical to those of the earlier sampling. Most essentially, the personality profile of the elite ballet dancer was validated as being marked by a narrow internal focus of attention, and such interpersonal characteristics as high levels of self-assurance, perfectionism, competitiveness, and need for control. It is concluded that with this profile available to represent a model personality on which success in dance may be predicated, there would be no reason not to proceed with using TAIS with dancers in the same way that it has been used for years with athletes — as a means to enhance the performance of those individuals who have made a career commitment to the field.
Assessing Hypermobility in Dancers
Authors: Desfor Fara G.
Published: May 2023

Many dancers have extreme joint mobility that can be an asset in the profession but may also put them at risk for injury. This article offers a brief review of the pathology, prevalence, and biomechani-cal implications of hypermobility as well as descriptions and evaluations of various mobility tests. A generally accepted tool for assessing hypermobility in dancers has yet to be developed but will probably need to distinguish acquired from inherited hypermobility and take into account different types and levels of dancer training.
Development, Reliability, and Validity of a Multistage Dance Specific Aerobic Fitness Test (DAFT)
Authors: Wyon Matthew , Redding Emma , Abt Grant , Head Andrew , Sharp N. Craig C.
Published: May 2023

The aim of this study was to design a multistage dance-specific aerobic field-test that would indicate whether a dancer had the cardiorespiratory capabilities to cope with the demands of dance class and performance. The test consisted of five progressively demanding dance sequences. The technical level of each stage was kept as simple as possible to reduce the effect of economy of movement so that the emphasis of the test was physiologically based rather than skill orientated. The reliability of the stage workloads was measured via oxygen uptake and heart rate using a tele-metric gas analyzer. After an initial familiarization trial, subjects (n = 56: 24 males and 32 females) undertook the test twice within 48 hours. The results showed significant differences in oxygen requirement and heart rates between stages (F [4, 172] = 803.522; p < 0.001) and gender (p < 0.01). The HR-VO2relationship for the test was r = 0.94; n = 3336; p < 0.001 and the SEE was ± 4.506. Reliability of the DAFT was calculated by determining the coefficient of variation (CV) expressed as a percentage and the percentage change in the mean between trials (% mean). CV ranged between 1.4 and 6.0 and % Amean between 0.2 and 6.3 for the stages. The use of dance specific moves and specific levels of the test equating to the mean oxygen demands of class and performance confirmed that logical validity had been achieved. Possible applications to the dance world are the monitoring of heart rate at each of the stages during the year; setting of a target stage attainment for an individuals readiness to undertake class or performance after injury and/or, setting specific aerobic capabilities for dancers post-holiday or for guest artists (below a specific mean heart rate during a designated stage).
The Effect of Positive Heel Inclination on Posture in Young Children Training in Flamenco Dance
Authors: Wilmerding Virginia , Gurney Burke , Torres Veronica
Published: May 2023

Flamenco dance requires male and female dancers to wear heeled shoes and learn to employ a stylized posture. Injury patterns of the adult flamenco dancer reveal that low back pain and self-reported injury is substantial. It is unclear what compensations are made in the normal spine to overcome the effects of acquiring this posture while standing in a heeled shoe. To prepare the beginning child dancer well for the rigors of this art form, it would be appropriate to know if the young performer exhibits the same postural strategies to compensate for the change in position of the foot in a heeled shoe. This study attempts to determine the degree and magnitude of changes of angulation in pelvic tilt in young dancers who were accustomed to standing in forced plantar flexion. Suggestions could then be made to teachers to prepare the body for the stresses that accompany training in flamenco dance. Sixteen children (10 girls, 6 boys) between the ages of 4 and 12 participated in this study. A Vicon 250 Motion Analysis System (Tustin, CA) was used to evaluate postural alignment by measuring the change angles of the joints of the lower body. No significant differences between the barefoot and heeled stance were revealed at the pelvis, hip, or knee. As expected, a paired t-test revealed that there was a significant change in the degree of plantar flexion of the ankle in the children when standing on a 2 inch platform (p = 0.001). The standard deviations of each site were quite large, which might account for the lack of a statistically significant difference between the two conditions. The children compensated in different, and opposite ways from each other. Children who dance in a heeled shoe might be at greater risk for injury because of the postural changes that accompany the chronic plantar flexed position. Although it must be recognized that there are many potential factors influencing back pain in the flamenco dancer, the reduction or change in the pelvic and lumbar region is a component. Teachers should make an effort to prepare students by increasing core strength and lower extremity flexibility as well as developing postural awareness and proprioception before the child engages in long and arduous flamenco training.
Electrocardiography and Echocardiography Findings in Contemporary Dancers
Authors: Whyte Gregory P. , George Keith , Redding Emma , Wilson Mathew , Lane Andrew , Firooz Sam
Published: May 2023

Alterations in cardiac structure and function as a result of chronic training have been extensively reported in the literature. To date, there is limited data on dancers. This study attempts to define cardiac electrical, structural, and functional characteristics in female contemporary dancers. Forty-four female full-time contemporary dance students (age: 23.0 ±5.6 years; height: 165.2 ± 7.9 cm; body mass: 59.2 ± 7.2 kg) volunteered for the study and underwent 12-lead electrocardiography and two-dimensional echocardiography. Echocardiographic results were compared with 30 age-matched and gender-matched controls. Sixteen percent (7/44) of dancers presented with sinus bradycardia (< 60 bpm) and seven percent (3/44) demonstrated shortened PR intervals (< 120 ms). Sokolow voltage criteria for left ventricular hypertrophy was observed in only 4% (2/44). Fourteen percent of dancers (6/44) demonstrated right axis deviation and nine percent (4/44) had incomplete right bundle branch block. One dancer exhibited nodal rhythm. Minor ST segment elevation (< 0.2 mV) was present in 7% (3/44) of dancers, and equally minor ST segment depression (< 0.2 mV) was present in 7% (3/44). Negative T waves and large T waves (>1.0mV) were observed in 14% (6/44) and 4% (2/44) of the dancers respectively. QRS and QT duration were within normal limits for all dancers. Echocardiography revealed no significant differences between dancers and controls for all structural and functional indices. It is concluded that contemporary dancers demonstrate limited cardiac structure and function changes compared to matched controls.
The Impact of Motivational Climate on Dance Students’ Achievement Goals, Trait Anxiety, and Perfectionism
Authors: Carr Sam , Wyon Matthew
Published: May 2023

This study examined whether dimensions of the perceived motivational climate in dance institutions could predict dancers’ levels of task and ego orientation, dimensions of trait anxiety, and dimensions of perfectionism. Participants were 181 English dance students (mean age: 18.5 years; SD: 2.0 years) from dance institutions in the United Kingdom. Participants completed surveys assessing their perceptions of the motivational climate, goal orientations for dance, trait anxiety, and perfectionist tendencies. Results of standard multiple regression analyses suggested that certain elements of the motivational climate were significant predictors of the dependent variables. Specifically, perceptions of dimensions of a performance-oriented climate were significant positive predictors of dancers’ ego orientation, elements of cognitive trait anxiety, and elements of neurotic perfectionism. Perceptions of dimensions of a mastery-oriented climate positively predicted dancers’ levels of task orientation. The findings are discussed with regard to the implications for dance pedagogy.
The Impact of Mirrors on Body Image and Classroom Performance in Female College Ballet Dancers
Authors: Radell Sally A. , Adame Daniel D. , Cole Steven P.
Published: May 2023

This study investigated the effect of teaching with mirrors on the Body-Areas Satisfaction component of body image and dance performance of female college ballet dancers. With the same instructor in two beginning ballet classes, 15 females were taught using mirrors and 15 females were taught without mirrors. Subjects completed the Cash 69-item Multidimensional Body-Self Relations Questionnaire (MBSRQ) during the first and last week of classes of a 14-week semester to measure body image. Dance instructors used the Radell Evaluation Scale for Dance Technique to assess students’ performance of the same adagio and allegro phrases danced during the fifth and fourteenth week of the semester. For the non-mirror class, there was a significant increase in adagio performance scores and a trend increase in allegro performance scores from pretest to posttest. Significant increases in adagio and allegro scores were not shown for the mirror class. Higher performing students, performing without the presence of the mirror, had increased Body-Areas Satisfaction scores on the MBSRQ. However, the higher performing students in the mirror class had decreased Body-Areas Satisfaction scores. These results suggest that the use of the mirror in a beginning ballet classroom may negatively affect the skill acquisition of the dancer and may contribute to the low body image scores of higher performing dancers.
Lisfranc Fracture-Dislocation in a Male Ballet Dancer during Take-Off of a Jump a Case Report
Authors: Kadel Nancy J. , Donaldson-Fletcher Emily A.
Published: May 2023

While initiating a jump, a male professional ballet dancer (28 years old) sustained an acute injury to his midfoot. Radiographs revealed a fracture-dislocation of the first and second tarsometatarsal joints, with dorsal dislocation of the proximal second metatarsal. Surgical treatment included open reduction and internal fixation of the first and second tarsometatarsal joints and the intercuneiform joints. This injury caused the dancer to retire prematurely from professional ballet dancing, despite restoration of anatomical alignment and reacquisition of full mobility in the foot and ankle. Follow-up radiographs at three years post-injury indicated maintenance of the reduction and signs of mild arthritis in the midfoot. The dancer resumed ballet dancing at a non-professional level. It is important for dancers to realize that acute Lisfranc injuries can end dance careers despite immediate treatment. Proper footwear and floor-surface maintenance are important for prevention of this injury.
Functional Characteristics of the Plantar Flexors in Ballet Dancer, Folk Dancer, and Non-Dancer Populations
Authors: Thomas Kathleen S. , Parcell Allen C.
Published: May 2023

This study compared values representing strength, power, and endurance of the plantar flexors within a female population consisting of non-dancers, folk dancers and ballet dancers. Forty-five females were divided into three groups (15 non-dancers, 15 folk dancers, and 15 ballet dancers; mean age: 21 ± 2 years). Similarities and differences in functional characteristics of the plantar flexors within all three groups were tested on a Biodex isokinetic dynamometer. The trials consisted of: 1, isometric contractions at angles of 80°, 90°, and 100° of plantar flexion; 2, peak torque and power at six isokinetic angular velocities at 60°, 90°,120°,180°, 240°, and 300° per second; and 3, a fatigue test consisting of 30 maximal concentric contractions at 300° per second, where the amount of work produced and the percentage of decline in work produced was measured. The non-dancers achieved significantly lower isometric strength peak torque values (149 ± 69 Nm) than the folk dancers (187 ± 69 Nm) and ballet dancers (171 ± 69 Nm). The two dance groups were not significantly different. Isokinetic peak torque for the non-dancers was significantly lower (45 ± 2 Nm) than the folk dancers (57 ± 2 Nm) and the ballet dancers (56 ± 2 Nm). The two dance groups were not significantly different. The data showed no significant differences in isokinetic measurements of power or percentage of decline in work in the fatigability trials. However, the folk dancers and ballet dancers produced significantly more work than the non-dancers in the same fatigability trials. Based on the data, dancers as a general group are clearly a separate and distinct population from the normal, healthy, non-dancing females with regard to isometric strength, isokinetic strength, and the ability to produce work over a period of time.
Flexibility in Dance
Authors: Deighan Martine A.
Published: May 2023

Dance, and in particular ballet, is characterized by beautiful body shapes and lines, much of which are due to flexibility. Without adequate flexibility, dancers are unlikely to raise themselves to professional standards. However, with such importance placed on this fitness-related parameter, there is a surprising lack of published data on dancers that examines flexibility in relation to injury risk and muscular performance. The following review summarizes the main findings from the dance, sports, and medical literature.
Stability in Dance Training
Authors: Phillips Craig
Published: May 2023

Stability training has become a recognized component of dance training in the past decade. Drawing on knowledge applied in sports and spinal rehabilitation, dancers are now able to enhance their performance by applying similar principles in their training. The main issue with stability training is one of being able to recognize the difference between muscle strength training and muscle skill acquisition. Motor control principles underlie stability training as it is the long-term, learned, skill of effective muscle recruitment that is desired rather than short-term strengthening of these muscles. We know that the musculoskeletal system is not an inherently stable structure and ultimately relies on muscle activity to maintain its integrity. This article explores both local and global stability muscle systems, the processes of skill acquisition, and highlight the differences between stability and rigidity.
A Critical Review of the Prevalence of Secondary Amenorrhea in Ballet Dancers
Authors: Chartrand Dominique , Chatfield Steven J.
Published: May 2023

The literature was evaluated in an effort to explain the apparently high prevalence and wide range of secondary amenorrhea reported for ballet dancers. In the general population the prevalence of secondary amenorrhea is between 2% to 5%. In the ballet community the prevalence of amenorrhea is 6% to 73%. Seven of the 22 articles assessed present a prevalence of secondary amenorrhea greater than 30% for ballet dancers. Due to lack of reported information within these studies, a better understanding of the data cannot be gained. Existing reports were found deficient in the following areas: activity level, caloric intake, menstrual log, specific subject information (rank, expertise, and individual and group data), standard definition of secondary amenorrhea, methods of data collection, lack of prospective studies, and recordings of hormonal contraceptives. To enable an evaluation and explanation of the prevalence of secondary amenorrhea in ballet dancers, new research should be undertaken to include all these variables in order to provide a more complete understanding.
The Injuries of Competitive Irish Dancers
Authors: McGuinness Donna , Doody Catherine
Published: May 2023

Objectives

The purpose of this study was to determine the rate and types of injury in competitive dancers of Irish Dance, establish the injury prevention measures used by dancers, and investigate any relationships between prevention measures and incidence of injury. There are no in depth published studies on injury rates or injury prevention strategies for Irish dance.

Methods

One hundred and fifty nine Irish dancers who were participants at the North American Irish Dance Championships (July 2-7, 2004) took part in this descriptive epidemiology study. Each participant completed a self administered questionnaire. The subjects were aged from 15 to 24 years (mean: 17.8; SD: 2.9). The number of years dancing ranged from 1 to 20 years (mean: 10.8; SD: 3.8).

Results

The results showed 79% (n = 125) of dancers had one or more injuries. The ankle (31%, n = 60) and foot (25%, n = 48) were the most frequently injured. Sixty-three percent (n = 121) of the dancers took over 21 days to recover from their injuries. Use of shock absorbent dance shoes significantly reduced the incidence of ankle injury (p < 0.0001). In addition warm up and cool down were associated with a decreased incidence of ankle injury (p < 0.0001 and p < 0.0001 respectively).

Conclusions

A variety of lower limb and in particular ankle injuries was reported by the competitive Irish dancers in this study. Injury prevention methods for ankle injury such as warm up, cool down, and use of shock absorbing dance shoes were associated with a decreased incidence of injury and warrant further investigation.
A Proposal for Standardized Psychological Screening of Dancers
Authors: Hamilton Linda H. , Solomon Ruth , Solomon John
Published: May 2023

Anatomic and physiologic screening of dancers, conducted on a regular basis, is by now a widely accepted aid to injury prevention and the enhancement of performance. The primary focus of screening procedures to date has been on assessing orthopedic and fitness parameters: on detecting those unique physical characteristics of the individual dancer that, in combination with the demands of the dance form being practiced, over time, may cause injuries or impede optimal performance. This is all well and good; however, it leaves unaccounted for the influence of the dancer's psyche, which, through the mind-body connection, can produce equally detrimental effects. It is the authors’ contention that the efficacy of virtually all screening procedures currently in use could be greatly increased by adding to them a comprehensive, standardized, psychological component. The purpose of this paper is to illustrate what such a component might look like, and to discuss some of the problems involved in, and important benefits to be derived from, its implementation.
Acetabular Labral Tears in the Dancer a Literature Review
Authors: Hartog Marika , Smith Jo , Zujko Andrea
Published: May 2023

Acetabular labral tears are recognized as a source of hip pain in the general, athletic and dance populations. The complicated, often end-range movement patterns required of dancers make them especially susceptible to hip injury. Labral tears at the hip can significantly impact the success of a dancer's career. Currently there is little research regarding acetabular labral tears in the dance population. This literature review highlights current knowledge of labral structure and function, the epidemiology and etiology of tears, and conservative and surgical treatment. According to the literature, labral tears are found most often in the anterior quadrant of the labrum. Both traumatic and nontraumatic mechanisms of injury are reported, of either minimal or significant severity. Physical therapy tests have poor specificity to diagnose labral tears. The majority of reviewed studies show positive outcomes post arthroscopy in the general population and in athletes. Further research is necessary to investigate optimum rehabilitation and long-term outcomes of conservative and surgical treatment for the dance population.
Measuring the Content of Dancers’ Images: Development of the Dance Imagery Questionnaire (DIQ)
Authors: Nordin Sanna M. , Cumming Jennifer
Published: May 2023

Mental imagery is the creation or re-creation of experiences in the mind and it is a common, yet under-researched area in dance. Indeed, although sport and exercise researchers have imagery measurement tools designed for their respective settings, no such tool has existed for dance. Having a valid and reliable questionnaire can produce information to form the basis for successful interventions to enhance both performance and well-being. Thus, the aim of this series of three studies was to create a questionnaire capable of assessing the frequency with which dancers image, entitled the Dance Imagery Questionnaire (DIQ). Studies 1 and 2 are primarily concerned with measurement development, while Study 3 also presents data that may be of more applied interest. A total of 1,068 female and male dancers from 25 dance forms and six experience levels (beginner to professional) participated in three cross-sectional questionnaire-based studies. There were 501 dancers in Study 1 (aged 23.26 ± 10.25 years), 317 dancers in Study 2 (aged 21.96 ± 6.63 years), and 250 dancers in Study 3 (aged 23.82 ± 9.16 years). Study 1 employed principal components analyses to determine that the DIQ consisted of 3 components: technique, mastery and goals, and role and movement quality. It was apparent that the mastery and goals component could also potentially split into two, producing a four-component solution. In Study 2, DIQ data were subjected to confirmatory factor analyses, from which a hierarchical solution emerged, with one higher-order factor and four second-order factors. The third study re-confirmed the hierarchical structure of the DIQ with a separate sample, and established the test-retest reliability of the questionnaire. Concurrent validity information is also provided concerning the relationships between dance imagery, imagery ability, self-confidence, and anxiety.
Anthropometric Factors Affecting Vertical Jump Height in Ballet Dancers
Authors: Wyon Matthew , Allen Nicolas , Angioi Manuela , Nevill Alan , Twitchett Emily
Published: May 2023

Jumping plays an integral part of ballet performance and this study examines some of the ballet dancer's characteristics that influence jump height. Forty-nine dancers (M = 21; F = 28) completed a series of tests that included two footed vertical jump height, single leg vertical jump height and anthropometric measurements. Supplemental training history and company position were also recorded. Statistical analysis (ANCOVA and MANOVA) indicated males had a greater vertical jump height than females (p < 0.01) and soloist and first artists had significantly greater vertical jump height than principals and artists for both male and females (p < 0.05). Anthropometric data indicated males having significantly larger leg girths than females. Males and females had no significant bilateral differences in girth measurements though male artists had significantly smaller thighs and calves than the other seniority levels (p < 0.05). Supplemental training did not influence jump height in this study's population though males carried out significantly more weight training (p < 0.01) and females more aerobic training (p < 0.05). When jump height was analyzed in relation to cross-sectional area of the calf and thigh, there was no gender difference (p > 0.05). These results corroborate to previous research and also provide greater insight on how anthropometric and choreographic factors potentially influence vertical jump height in ballet dancers. The ineffective influence of supplemental training on vertical jump height needs greater examination. How other training regimens could influence jump height in dancers needs to be examined.
Revisiting Overuse Injuries in Dance in View of Motor Learning and Somatic Models of Distributed Practice
Authors: Batson Glenna
Published: May 2023

One hallmark of dance education is rigor-ous and repetitive physical practice. Of the many unifying theories of motor learning, the “power law of practice” states that repetitive practice of physical movements is a necessary ingredient in improving performance. Compelling evidence exists, however, showing that practice conditions where rest intervals are interspersed be-tween movement repetitions (“distributed practice”) play a strategic role in the acqui-sition and consolidation of learning motor skills. Further, repetition without adequate rest is implicated in overuse syndrome and has injurious consequences in both the peripheral and central nervous system. This article summarizes the research from neuroscience and motor learning on distributed practice conditions within the context of overuse injuries in dance. The neural consequences of repetitive movement without rest (adequate rest-to-activity ratios) are discussed. Schedules designed to promote motor skill learning and avoid overuse (adopted in somatic education, sports, and martial arts) are reviewed in the light of the current philosophy underlying dance practice schedules. Finally, the paper points to need for future research in designing protocols with higher rest-to-activity ratios in dance classes.
A Descriptive Analysis of Kinematic and Electromyographic Relationships of the Core during Forward Stepping in Beginning and Expert Dancers
Authors: Chatfield Steven J. , Krasnow Donna H. , Herman Amanda , Blessing Glenna
Published: May 2023

While electromyographic (EMG) and ki-nematic data in dance are accumulating, to date these data have raised more questions than they have answered. The purpose of this study was to introduce ensemble averaging into this body of literature as a way of dealing with the high levels of within-subject and between-subject vari-ability that have been previously reported. This study also introduces analysis during a forward weight shift, an analysis currently absent from the literature. Three collegiate novices (18.7 ± 0.6 years of age) and three expert dancers (27.7 ± 5.5 years of age) were studied in-depth. EMG data were collected continuously at 600 Hz for analysis of onset of activity for abdominal and erector spinae muscles. Kinematic data were collected continuously at 120 Hz from markers on the acromion and the greater trochanter for analysis of the verticality of the trunk. Data were collected continuously for over 4 seconds to include: baseline data prior to movement on a right legged balance, data for movement into plié fondu on the right leg, data for a forward step to the left leg, and baseline data at resolution on a left legged balance. For analysis, data were synchronized by time using onset of vertical ground reaction forces recorded by a force plate under the initial stance leg. All participants were tested on two separate days to assess day-to-day variability. Fifteen trials were collected on each day for each individual. Ensemble averaging of continuously recorded data was used to create line graphs for visual inspection, first to compare day-to-day congruence for each individual, next to assess within group variability, and finally to compare composite graphs between groups. Day-to-day variations for each individual were minimal. Differences were seen between members of the Beginner group but not the Expert group. Between group comparisons revealed the following differences: Experts appeared to use an anterior core support strategy while Beginners appeared to use a posterior core support strategy, Experts dis-played less EMG and kinematic variability than Beginners, and Experts maintained a more vertical posture throughout. Surprisingly, even though Experts were more verti-cal, they demonstrated the same amount of overall anterior-posterior sway as the Beginners. This finding leads to discussion of the dynamic nature of neuromuscular coordination patterns in maintenance of verticality. Issues surrounding the inability of statistically constructed models of human kinematic data to accurately represent individuals in groups are also discussed. Finally, applications of these findings to teaching and learning are offered.
Musculoskeletal Pain, Disability and Quality of Life among Retired Dancers
Authors: Rönkkö Reetta , Markku Heliövaara , Malmivaara Antti , Roine Risto , Seitsalo Seppo , Sainio Päivi , Kettunen Jyrki
Published: May 2023

The aim of this study was to examine the long-term effects of professional dancing by comparing the prevalence of musculoskeletal complaints between retired dancers and the general population. A structured questionnaire on the history of regional pains, disability, and overall health was mailed to all available retired members of the Finnish National Ballet (n = 37) and to all retired members of the Union of Finnish Dance Artists (n = 32). An age-matched pool of non-dancer controls (n = 631) was chosen from the Health 2000-Survey to represent the general Finnish population. Disability, overall health and quality of life were assessed using the Visual Analogue Scale (VAS). Differences in the occurrence of musculoskeletal complaints between dancers and controls were analyzed with a logistic regression model. The relative risks were evaluated as odds radios (OR) with 95% confidence intervals. Adjusted mean values of VAS scores were estimated using a generated linear model. The mean age of the ballet dancers was 59 years (range: 49 to 71 years) and that of the modern dancers 50 years (range: 42 to 62 years). Adjusted for age and sex, the risk, OR (95% CI in brackets), of walking difficulty or limping because of hip pain during the past month was 2.9 (1.3-6.3) in the retired dancers (ballet and modern combined) compared with the general population. With similar adjustments, the OR for a knee complaint was 3.7 (1.8-7.5) in the former dancer group in comparison to the controls. The risk of suffering from walking difficulty or limping because of hip or knee pain is significantly increased in dancers as compared to non-dancing controls. The walking difficulty and limping because of hip and knee pain are noteworthy symptoms when assessing a former dancers musculoskeletal health.
Contribution of the Pelvis to Gesture Leg Range of Motion in a Complex Ballet Movement
Authors: Wilson Margaret , Ryu Joong-Hyun , Kwon Young-Hoo
Published: May 2023

Eight skilled ballet dancers performed grand rond de jambe en l'air with the right leg as gesture leg at heights of 90° and 105° as well as their maximal active range of motion (MAR). Three-dimensional motion analysis was performed to quantify the pelvis and gesture-leg motions and to investigate the interaction between pelvic motion and increased leg height. Orientation angles of the pelvis and relative orientation angles of the gesture leg to the pelvis were computed. Events for analysis were defined based on the gesture leg motion, and the pelvis and gesture leg orientation angles at these events as well as the peak values were obtained. One-way repeated-measure ANOVA was used to determine differences among leg heights (p < 0.05). In grand rond de jambe of 90° or higher, dancers gradually increased pelvic motion, especially anterior-posterior and lateral tilts, as the gesture leg height increased. Approximately 4% to 16% of the leg height at end of the ascending motion and 60% of the leg height at initiation of the descending motion were explained by posterior and anterior pelvic tilt, respectively. Maximum left lateral pelvic tilt was equivalent to approximately 45% to 60% of the maximum hip abduction. As the leg height requirement increased, dancers achieved this height primarily by increasing pelvic motion. Gesture leg motion revealed only a minor contribution. In spite of literature in dance pedagogy that suggests that the pelvis should remain immobile during grand rond de jambe, the authors conclude that the pelvis is the primary contributor to the gesture leg range of motion for increased vertical angle demands.