Journal of Dance Medicine & Science最新文献

Background: Achilles tendinopathy can be a devastating condition in ballet dancers. Initial medical evaluation is frequently conducted by generalist physicians, who may lack the perspective of dance and sports medicine focused training and often prescribe complete rest for chronic overuse injuries. In order to provide targeted information about Achilles tendinopathy and the unique needs of elite athletes, such as ballet dancers, we designed an educational intervention that covers relevant anatomy, physiology, biomechanics, clinical presentation and evaluation, and recommendations for initial treatment and sub-specialty referral. The objectives of this study were to determine baseline understanding of Achilles tendinopathy by generalist physicians and to evaluate the efficacy of an educational intervention on their knowledge.

Methods: This was a prospective pre- post-test study, to measure improvement in knowledge about Achilles tendinopathy. Emergency Medicine and Primary Care physicians participated in an educational intervention with didactic and hands-on components. Data were analyzed using a two-tailed t-test.

Results: Twenty generalist physicians participated. There was significant improvement in their knowledge of Achilles tendinopathy for all our educational objectives (Pre-test: 59% correct answers; post-test: 79% correct answers; P < .0001; 95% CI: 6.32-10.78.).

Conclusions: A brief educational intervention leads to increased knowledge of Achilles tendinopathy in generalist physicians. By increasing awareness of Achilles tendinopathy through a standard educational model, we propose that our curriculum can be portable and accessible to all health care providers who encounter dancers and other athletes with Achilles tendinopathy and may serve as a model for expanded education to generalists about other conditions commonly encountered in ballet dancers.

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.

Introduction: Dance is a physically demanding art form that often results in musculoskeletal injuries. To effectively treat these injuries, standardized and reliable assessment tools designed to the dancer's needs are required. Thus, the aim of this review is to identify studies that have employed validated tools to assess musculoskeletal injuries in ballet, modern, and contemporary dancers, focusing on describing the content and psychometric quality of the tools used. Methods: This systematic review is registered at PROSPERO (CRD42022306755). PubMed, Cochrane, LILACS, Web of Science and SPORTDiscus databases were searched by two independent reviewers. Articles assessing musculoskeletal injuries with validated tools in ballet, modern and/or contemporary dancers and written in English, Portuguese, or Spanish were included. Non-peer reviewed articles, books, conference abstracts, thesis/review articles, or case design studies were excluded. The original validation studies were compiled when necessary. Two independent reviewers conducted a standardized data extraction and evaluated the methodological quality using an adapted Downs and Black checklist. Results: From the 3933 studies screened, 172 were read to verify if they met the inclusion criteria, resulting in 37 studies included accounting for 16 unique validated tools. Two were imaging exams, one was an injury classification system, and 13 were self-reported injury questionnaires. Only four injury assessment tools were validated for dancers, emphasizing the need for further validation studies for the dance population. Most of the articles (57%) achieved high-quality methodological scores and the remaining (43%) reported medium-quality scores. Conclusions: Valid, reliable, and specific tools to assess dance injuries are lacking in general. For enhanced methodological rigor in future studies, the incorporation of validated tools is recommended to improve methodological quality and facilitate cross-study comparisons. Researchers may consider conducting validation studies, involving processes such as translation into another language, validation of modifications to the original tool, or reporting reliability within the article itself.

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.

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.

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.

Aim: To investigate quality of life (QoL) measures in a cohort of young female dancers. Methods: Cross-sectional survey study design was utilized to study dancers 8 to 17 years enrolled in two elite dance schools in the Boston area. The main outcome measure was the Pediatric Quality of Life (PedsQL 4.0) questionnaire, a validated QoL survey for children, with established normative values for comparison. Demographics and questions pertaining to training regimens and injury/illness history were also included. Sub-groups (8-11 years, 12-14 years, and 15-17 years) were created to analyze outcomes by age. Results: One hundred and forty emails were delivered, 72 were completed and included in the final data analysis (51.4%). The median scores for physical, psychosocial, emotional, social, and school PedsQL sub-scales were 87.5, 90.0, 80.0, 100.0, and 92.5, respectively. The median score of the total PedsQL scores was 88.8. No difference in QoL outcomes by age group was found (physical: P = .328; psychosocial: P = .918; emotional: P = .673; social: P = .573; school: P = 0.962; total: P = 0.766). 52.5% of the participants responded that they regularly perform in shows. Median hours/week of dance rehearsal was 10 hours (mean ± standard deviation: 10.3 ± 4.9; 95% CI: 9.0, 11.6; IQR: 7.0, 13.5; range: 2.0, 20.0) and 68.9% reported they practice and rehearse throughout the entire calendar year as opposed to solely during the school year; most dancers reported participating in dance 11 months (median value) per year (mean ± standard deviation: 10.7 ± 0.8; 95% CI: 10.5, 11.0; IQR: 10.0, 11.0; range: 9.0, 12.0). Conclusion: QoL measures for young female dancers were higher relative to existing data for the general population and lower compared to other sports participation. These results will support the social, emotional, and physical health of young dancers.

Background: While the previous research has made crucial developments in a dance-specific version of the SEBT, current modifications to the SEBT have not conclusively produced a valid dance-specific dynamic balance test. Purpose: The aim of this paper was to utilize the most practical dance-specific variations from previous research and incorporate them into a reliable test to be considered for future screenings for dancers. Methods: Twenty-one female dancers voluntarily took part in the research (age: 20.86 ± 3.68 years). This protocol consists of 3 stages, each increasing in difficulty; stage one: dsSEBT Average Tempo, stage two: dsSEBT Block, and stage three: a combination of stage 1 and stage 2, the dsSEBT Average Tempo on Block. Reach distance (% of limb length), error scores, and average time to complete each stage were recorded. A stage completion criteria was developed to move from one stage to the next wherein certain reach distance and error score standards needed to be met. Results: Between previous research using the same participants and the current study, each reach direction exhibits a statistically significant correlation (P < .05) with good to excellent ICC values ranging from .750 to .918, suggesting that test-retest reliability is high. Overall, 90.48% of participants succeeded in passing stage one, 19.05% of total participants passed stage two, and only 4.76% of the 21 participants passed all 3 stages with statistically significant differences detected for reach distance and incomplete trials between stages (P < .05). Conclusion: This data suggests that the test is challenging enough to show dancers weaknesses and push the limits of their balance capabilities. With a clear increase in difficulty from stage to stage, the test adds layers of demanding tasks designed to test the dancer proprioceptively.

Introduction: Dance, as a performance activity, is associated with various problems. Among these challenges, sleep disturbances are notably prevalent. Aims: This study aimed to explore the potential relationship between sleep characteristics-specifically chronotype and subjective sleep quality- and psychological inflexibility in dance students. Methods: This research adopted a cross-sectional design using non-probabilistic sampling. The data were collected in paper format by visiting public conservatories and private academies, and online. One hundred fourteen dance students, with a mean age of 23.87 years, participated in the study. Assessment tools included the Acceptance and Action Questionnaire-II, Pittsburgh Sleep Quality Index, and the Composite Scale of Morningness. Results: The results revealed that 80.7% of all students reported poor sleep quality, compared to 19.3% who reported good sleep quality. Differences emerged in both subjective sleep quality (F_{(2, 113)} = 4.825, P = .010) and chronotype (F_{(2, 113)} = 6.172, P = .003) when students were grouped according to low, medium, or high levels of psychological inflexibility. Those with low inflexibility, as opposed to those with high inflexibility, report better sleep quality, with no differences observed between medium and high inflexibility groups. Students with high-medium levels of psychological inflexibility showed a higher risk (OR = 6.373 times higher) of experiencing poor sleep quality compared to those with low psychological inflexibility. In terms of chronotype, the low inflexibility group is inclined to be more of a morning type than the medium and high inflexibility groups, with no differences between the latter 2 groups. Students categorized as having low inflexibility tend to have a longer history of dancing under the guidance of a teacher and dedicate more hours and days per week to rehearsal. Conclusion: Conservatories can become "healthy spaces." In this regard, sleep hygiene programs and Acceptance and Commitment Therapy interventions can provide guidance to professionals working with dancers in professional companies and conservatories.

Introduction: Research investigating the physiological demands of dance performance has documented exercise intensity and time spent in work and rest; however, available data are across limited dance genres and often use rehearsal or simulated conditions. Real-time data recorded during live performance with an audience are limited. The aim of the study is to provide a detailed description of the physiological demands of live professional Irish dance performance. Method: The entire Irish dance cast of Riverdance participated in the study (n = 24). Approval was granted by the Institutional Research Ethics Committee. Matinee and evening performances on the first day of a tour were examined in a descriptive, cross-sectional design. Heart rate (HR) monitors worn discretely under costumes recorded data every 5-seconds. Video analysis allowed calculation of time spent in work and rest. All descriptive analyses were split by role (troupe/lead) and sex (male/female). Results: Dancers worked at hard/very hard intensities (mean > 72%, peak > 91% HR_max) for ~3 minutes at a time for 3-9 individual dance numbers. There was a high variation in overall demand experienced by individual dancers due to variation in both duration and intensity of on-stage time, dependent upon their role. Mean total on-stage time was 18.18 ± 5.82 minutes, 19.43 ± 5.80 minutes, 29.71 ± 0.62 minutes, 20.00 ± 0.00 minutes for male troupe, female troupe, male lead, and female lead dancers, respectively. Recovery periods were varied in terms of duration, activity undertaken, and HR response. Conclusion: Individual dance numbers within a professional Irish dance show were high intensity for a short duration when considered in isolation, but overall physiological demand experienced by any one dancer across the entire show varied dependent upon their role and off-stage/recovery practices. Future research investigating the physiological demands of dance performance should ensure analysis accounts for the individual dancer's role and should capture the entire show duration in repeated exposures.