Journal of Dance Medicine & Science最新文献

Introduction: Measurement of performance quality in dance is important but challenging and few dance performance quality measures exist. This study aims to (1) identify and (2) assess the quality of dance performance outcome measures for ballet, modern and contemporary dance. Methods: A 2-step systematic review with two separate literature searches was conducted. Step 1 involved a systematic review to identify all ballet, modern and contemporary dance performance quality outcome measures. Step 2 involved a systematic review to identify studies that reported measurement properties (eg, validity, reliability) of the tools identified in Step 1. A comprehensive electronic search of MEDLINE, SPORTSDiscus, CINHAL, Embase and IADMS Bibliography was conducted from inception to November 2020 (Part 1) and February 2021 (Part 2). To evaluate the quality of each dance performance outcome measure, three steps were conducted (1) assessment of methodological quality using the COSMIN checklists, (2) evaluation of results against criteria of good measurement properties and (3) summary of the evidence and an overall rating of evidence using a modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results: Fifteen dance performance quality outcome measures were identified (Step 1). Seventeen studies reported measurement property data for 14 of 15 identified outcome measures (Step 2). The majority of the 34 measurement property outcomes were rated as doubtful (COSMIN checklists), and demonstrated sufficient measurement properties. Only one outcome measure, the Radell Evaluation Scale for Dance Technique (RESDT), was assessed as having low and moderate quality evidence for validity and reliability respectively. The remaining 13 tools were rated as having very low-quality evidence (GRADE criteria). Conclusions: Due to low quality, the 15 dance performance quality tools cannot be confidently recommended for use at this time. Dance teachers, clinician and researchers should consider feasibility issues and use the tools with caution until adequate high-quality evidence is available.

Introduction: Ballet demands diverse physical prowess, requiring dancers to execute movements symmetrically, irrespective of their dominant leg. Ballet often includes jumps, including the basic open-leg leap-the grand jeté-which requires uniform performance regardless of the leg on which the leap is initiated. However, no studies have simultaneously evaluated the effects of dominant leg or movement variation on jump height, leg split angle, jump time, and floor reaction forces during take-off and landing, which are related to the feeling of floating in the grand jeté. This study aimed to determine whether the high-level, stable, and beautiful performance required of professional ballet dancers in the grand jeté is affected by the dominant leg. Methods: Twelve female ballet dancers, all right leg dominant, performed the grand jeté 3 times on each side, distinguishing between dominant (right leg landing) and non-dominant (left leg landing) grand jetés. Utilising 3D movement analysis, we measured jump height, jump time, maximum leg split angle, and maximum vertical ground reaction force (VGRF) during take-off and landing. Mean values and coefficients of variation were calculated for each analysed parameter. Paired sample t-tests were conducted to assess differences between left and right grand jetés, with a significance level set at P < .05. Results: Statistically significant differences were observed in jump height (P = .028) and jump time (P = .001) when comparing the average of three trials for each side. However, no significant differences were found in maximum leg split angle (P = 0.643), maximum VGRF at take-off (P = .200), and maximum VGRF at landing (P = .109). In addition, no significant differences in coefficients of variation were identified for all items. Conclusion: Ballet dancers showed consistent performance on dominant and non-dominant legs but higher and longer jumps for grand jetés landing on the dominant leg, which may have affected overall performance.

Purpose: This study examined risk and protective factors in dancers with/without posttraumatic stress disorder (PTSD) and with/without trauma exposure.

Literature review: Exposure to traumatic events and developing PTSD can compromise daily functioning and performance ability. Despite exposure many dancers adapt, whereas others suffer psychopathology such as depression, anxiety, PTSD, and difficulties regulating emotions.

Methods: Two hundred ninety two pre-professional/professional dancers provided informed consent (IRB approved) and completed 8 self-report measures. A subsample (66%) exposed to a significant traumatic event was evaluated for PTSD. Multivariate analyses of covariance (MANCOVA) were conducted to compare dancers with/without PTSD and with/without trauma exposure. A logistic regression analysis determined predictors of PTSD.

Results: The MANCOVAs indicated that dancers exposed to trauma (66%) and who had PTSD (32%) had significantly more difficulty regulating emotions, engaged more emotion-oriented coping under stress, and had increased depression, trait anxiety, and cumulative trauma. In these group comparison analyses there were non-significant differences regarding flow experiences and task- and avoidance-oriented coping strategies. In the logistic regression analysis childhood physical and sexual abuse, childhood emotional neglect, mental illness within the family, and difficulty disclosing abuse experiences were predictors of PTSD. In the total sample 21% had PTSD.

Discussion and conclusions: This study identified types of abuse/trauma, emotion regulation/coping, and psychopathology associated with PTSD in dancers exposed to trauma (66%) and with PTSD (32%). In the total sample 21% had PTSD. Regardless of exposure to trauma or PTSD, the non-significant findings indicated similarities for dancers for global and autotelic flow experiences and task- and avoidance-oriented coping strategies. These positive factors may mitigate trauma-related symptoms. It is recommended that dancers, educators, and clinicians understand the effects of trauma exposure and promote the development of effective coping strategies, emotion regulation, and flow states which may diminish the negative effects of PTSD.

Introduction: In classic ballet, choreography often involves tiptoe standing. Tiptoe standing requires a high and stable foot arch structure, which is achieved by contraction of the plantar intrinsic foot muscles (PIFMs). Long-term repetitive loading with a specific movement can induce hypertrophic adaptation of the associated muscles. For dancers, however, limited information on the size of individual PIFMs is available from previous studies. The purpose of this study was to determine the differences in the sizes of 10 individual PIFMs between dancers and non-dancers.

Methods: Muscle volumes (MVs) of 10 individual PIFMs were measured using magnetic resonance imaging in 15 female dancers and 15 female non-dancers. Muscles analyzed included abductor hallucis, flexor digitorum brevis, abductor digiti minimi, quadratus plantae, lumbricals, flexor hallucis brevis, adductor hallucis oblique head, adductor hallucis transverse head, flexor digiti minimi, plantar/dorsal interossei. In addition to absolute MVs, relative MVs normalized to body mass (rMV_BM) and the percentage of individual MVs relative to the sum of 10 individual PIFM MVs (%MV_WHOLE) were calculated.

Results: The absolute MVs of 6 individual PIFMs, including the flexor digitorum brevis and lumbricals, were +16% to 59% larger in dancers than in non-dancers (P ≤ .048). The rMV_BM of all individual PIFMs were +35% to 95% larger in dancers than in non-dancers (P ≤ .019). The %MV_WHOLE of the flexor digitorum brevis and lumbricals were +10% to 36% higher (P ≤ .014) and those of the abductor digiti minimi and adductor hallucis oblique head were +8% to 11% lower (P ≤ .037) in dancers than in non-dancers.

Conclusions: For all 3 MV measures, only the flexor digitorum brevis and lumbricals, which are functionally specialized for flexion of the second to fifth metatarsophalangeal joints, were consistently larger in dancers than in non-dancers. This may be due to long-term repetitive loading on these PIFMs during ballet training involving tiptoe standing.

Introduction: While several studies have analyzed the characteristics and burden of injuries and physical complaints in (pre-)professional dancers, mental health problems, other than eating disorders, have rarely been studied in professional ballet dancers. The aims were to (a) investigate the prevalence of self-reported mental health problems, and (b) analyze their potential associations with sleep disturbance, coping skills and social support in professional ballet dancers. Methods: During a pre-season health screening, professional ballet dancers of three companies were asked to answer questions on personal characteristics, current need and attempt to lose weight, chronic/recurrent mental health problems, and need of support from a psychotherapist as well as established questionnaires on depression (PHQ-9), generalized anxiety (GAD-7), eating disorders (EDE-QS), sleep disturbance (ASSQ), athletic coping skills (ACSI-28) and perceived social support (F-SozU-K6). Results: All 96 dancers (average age 27.3 years, 51.0% male) who participated in the screening answered the questionnaire. In the PHQ-9, 19 (19.8%) dancers reported mild, and 4 (4.2%) moderate to severe symptoms. In the GAD-7, 19 (19.8%) dancers reported mild, 11 (11.5%) moderate and three (3.1%) severe symptoms. Ten (10.4%) dancers were screened positive for an eating disorder in the EDE-QS. Almost two thirds of the dancers reported sleep problems of mild (n = 39; 40.6%), moderate (n = 19; 19.8%) or severe extent (n = 3; 3.1%) in the ASSQ. One in five dancers (n = 19; 19.8%) wanted or needed support from a psychotherapist at the time of the screening. The mean score of ASSQ correlated significantly with PHQ-9 (r = .34; P = .001) and GAD-7 (r = .27; P = .008). Correlations of mental health problems with athletic coping skills and social support were generally low. Conclusion: The prevalence of mental health problems, especially anxiety and eating disorders, was high in professional ballet dancers. Routine screening of mental health and sleep problems as well as interventions to improve mental health and sleep quality are strongly recommended. Level of Evidence: 2b cross-sectional study.

Background: Mindfulness and acceptance-based approaches have been trialled in professional sport. The present pilot study was a randomized controlled trial with professional ballet dancers investigating the effectiveness of the Mindfulness-Acceptance-Commitment (MAC) approach, developed for athletes, compared to an education program which included topics relevant to ballet and performance. Methods: Participants included 16 professional ballet dancers (2 men and 14 women) who were randomly assigned into either the MAC or education group for 1 session per week, for 6 weeks. Participants were assessed pre-and post-intervention using the Mindfulness Inventory for Sport (MIS) and the Acceptance Action Questionnaire (AAQ-II). Within 2 weeks of the final mindfulness session, all participants completed a semi-structured interview. Results: No differences were found when comparing the questionnaire responses between pre- and post- intervention, nor between the MAC group and the control group at post intervention for all subscales. Although dancers reported in the interviews that the sessions were valuable, they advised their ability to dedicate time to mindfulness ongoing would be challenging. Conclusions: Mindfulness interventions, as explored in this study, show promise to promote the well-being of professional ballet dancers. For consistent and ongoing mindfulness practice, future designs should seek to embed mindfulness practice into dancer and company schedules.

Background: Objective assessment of ballet execution remains limited by the subjective nature of expert evaluations, which often integrate stylistic interpretation and artistic expression. Objective: This study introduces the Qualitative Assessment of Ballet Kinematics (QABAK), a computational framework that models ballet jumps within a low-dimensional biomechanical space. QABAK evaluates execution quality using four targeted parameters: Recovery Effectiveness (RE), Slap Coordination (SC), Grand Battement (GB), and Ballon Efficiency (BE). Methods: Motion capture data from professional dancers performing the Glissade Saut de Chat (GSDC) were analyzed using QABAK. Computed scores were compared to expert assessments based on the Performance Competence Evaluation Measure (PCEM). Results: QABAK rankings demonstrated strong alignment with expert evaluations while exhibiting reduced score variability. Each parameter captured distinct biomechanical features contributing to jump quality. Conclusion: QABAK offers a structured, repeatable method for evaluating ballet movement that may complement expert judgment while reducing subjective variance. Its use of biomechanical decomposition within a simplified execution space highlights a promising approach to performance analysis in dance.

Background: The prevalence of Idiopathic Scoliosis (IS) is 2% to 3% in the general population. The presence of a hump can be detected clinically, but only X-rays can confirm the diagnosis. Early detection and treatment can prevent IS progression and complications. There is a lack of knowledge about the actual prevalence and predictors of IS among dancers.

Purpose: To investigate the prevalence of IS in dancers, how it is diagnosed and classified, and explore possible predictors. Study Design: Prevalence systematic review with meta-analysis.

Methods: PubMed, Embase, Scopus, CINAHL Plus databases and the Cochrane Central Register of Controlled Trials were searched up to August 2024.

Study selection criteria: Original research involving dancers who received a diagnosis of IS and reporting a measure of its prevalence, or sufficient data to compute it, were included.

Data synthesis: Random-effects model meta-analysis. The risk of bias was assessed using the Joanna Briggs Institute checklists. The certainty of evidence was judged using the GRADE approach.

Results: Fifteen studies, accounting for 5709 dancers aged 8 to 41 years, were included in the analysis. The overall prevalence of IS was 15.8% (10%-22%). When X-rays were not performed, clinical examination alone skewed the prevalence, making it appear 48.1% to 73.4% higher.

Conclusions: The prevalence of IS in dancers, regardless of level of training or age, has been found to be at least three times higher than in the general population. However, the lack of standardized assessment and diagnostic tools makes these results questionable. Dancers' screening for scoliosis, with standardized testing procedures, should be used for X-rays referral, to allow for early diagnosis and treatment.Trial RegistrationRegistered on PROSPERO the 01/05/2023: CRD42023418019.

Introduction: Spontaneous intracranial hypotension (SIH) is a condition caused by a cerebrospinal fluid (CSF) leak, leading to a drop in intracranial pressure. SIH typically results from a spontaneous dural tear, often linked to connective tissue disorders, minor trauma, or repetitive spinal stress. Among dancers, especially in professional ballet, the risk of SIH may be increased by repetitive spinal hyperextension and strenuous movements. Ballet movements, such as the cambré, place significant stress on the spine, potentially leading to CSF leaks. Recognizing the signs of SIH, which often presents with orthostatic headaches and lumbar pain, is critical for timely intervention and recovery, especially in athletes like dancers where functional recovery is paramount. Methods: We report the case of a professional female ballet dancer who presented with severe orthostatic headache and lumbar pain after a hyperextension injury during a ballet performance. Brain magnetic resonance imaging revealed pachymeningeal enhancement and a CSF fistula at the T11 level, confirming a diagnosis of SIH. Conservative treatment, including bed rest, high fluid intake, and caffeine failed to relieve symptoms. Multiple blind blood patches and a fluoroscopically targeted patch were also unsuccessful. Results: Definitive management was achieved via epidural patching with fibrin glue, which corrected the dural defect. A specialized physical therapy regimen focusing on spinal stabilization, core strengthening, and gradual reintroduction of dance-specific movements was essential for her recovery. This approach aimed to reduce the risk of recurrence and safely transition the patient back to dance. Conclusion: SIH can result from hyperextension injuries in dancers, underscoring the importance of early diagnosis and multidisciplinary management. While conservative measures may fail in some cases, surgical correction, followed by a targeted rehabilitation program, plays a crucial role in full functional recovery. A rehabilitation program tailored to the demands of professional dancing is essential to minimize long-term complications and support a safe return to performance.

Introduction: Leg asymmetry is common in many sports, including dance. Ten-sao, a fundamental practice movement in Khon masked dance, involves symmetrical continuous movements where dancers perform strong stomping actions. Objectives: to compare ground reaction forces (GRFs) and calculate the absolute symmetry index (ASI) between dominant and non-dominant legs during Ten-sao in Khon masked dancers. Methods: Fifteen healthy male Khon masked dancers with at least 5 years of experience participated in the study. Each dancer performed Ten-sao continuously for 10 cycles. The GRFs of each leg were assessed using two force plates, capturing in the vertical, antero-posterior, and medio-lateral directions during different phases of the Ten-sao dance. The ASI was calculated to assess symmetry in GRF distribution. Results: A significant difference in vertical GRF was found during the single-leg stance phase, with the dominant leg exhibiting greater force than the non-dominant leg (P = .023). The median and interquartile range (IQR) for the dominant leg was 90.005 N/kg (IQR 9.73), while the non-dominant leg exhibited a median of 57.494 N/kg (IQR 8.401). These findings highlight the asymmetry in force production between the dominant and non-dominant legs. The ASI showed asymmetries in the antero-posterior direction during double-leg support (DLS), and in the antero-posterior and medio-lateral directions during peak GRF (pGRF). Further asymmetries were observed in the antero-posterior, medio-lateral, and vertical directions during single-leg standing (SLS). Conclusion: The study reveals significant leg asymmetry in vertical GRF between the two legs among Khon dancers performing Ten-sao. The dominant leg demonstrates higher vertical force during SLS, and various asymmetries are presented in both DLS and SLS phases. Addressing these asymmetries in training programs is crucial for enhancing performance and reducing injury risk for Khon masked dancers.