Journal of Dance Medicine & Science最新文献

Introduction: Promoting physical wellness for preschool-aged children with developmental disorders (DD) is a known challenge. Interventions are more likely to succeed when physical activity opportunities are available to children within the context of their typical environments. We evaluated the feasibility and preliminary effect of 1 potential solution: structured creative dance classes delivered within a preschool environment.

Methods: Using a non-randomized feasibility study design, we offered physical activity in the form of creative dance classes for children with and without DD within an inclusive preschool. Classes lasted 30 minutes and were held once a week or 7 weeks. We measured attendance (primary), observed active participation (% of class duration), and balance (Pediatric Balance Scale). Non-parametric descriptive statistics are expressed as median (interquartile range). Balance was evaluated regarding (a) difference between groups at baseline (Mann-Whitney statistic) and (b) intervention effect for children with DD (1-tailed, paired t-test).

Results: Twelve preschoolers (age range = 3-5 years) participated: 4 with DD and 8 with neurotypical development. Attendance was 93% (79%-100%) for children with and 100% for children without DD. Per class, rate of active participation in dance activity was 33% (28%-45%) for children with and 80% (71%-82%) for children without DD. Starting balance scores were lower (P = .014) for children with DD (42 (39-45)) compared to those without (51 (50-52)). Post-intervention, balance scores improved for the children with DD to 50 (50-51) (df = 3, p = .014, t-statistic = 2.35); each child with DD surpassed minimal detectable change for balance.

Conclusion: Creative dance classes, delivered within an inclusive preschool environment, are feasible for some preschool-aged children with DD to participate in and efficacious as a physical training challenge at low activity doses. More study is warranted of this potential solution to meet the need for physical wellness promotion among young children with DD.

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: 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.

Introduction: The menstrual cycle is an important indicator of health in female athletes. Female elite adolescent dancers are expected to control their weight while also training intensely, which can lead to menstrual disorders. This study aimed to investigate the relationship between body composition and menstrual status in female elite adolescent dancers. Methods: In total, 131 female elite adolescent dancers (age: 15.9 ± 1.5 years) were enrolled in this study. We measured the height, weight, and body fat percentage (BFP) for each participant and calculated their body mass index (BMI). We gathered information on individual menstruation patterns and the participants' menstrual cycles over the previous year using recall methods. We then compared the differences between dancers with menstrual cycle disorders and those without. Primary amenorrhea was defined as menarche occurring after the age of 15, while secondary amenorrhe was defined as experiencing fewer than 5 or no menstrual periods for at least 3 of the previous 12 months. We conducted a reliability test using the same questionnaire 2 weeks later. Statistical significance was defined as P < .05, and we calculated the effect sizes (d) and 95% confidence intervals (95% CI). Results: The average BMI and BFP were 22.6 ± 3.0% and 19.4 ± 2.2 kg/m², respectively. Low BFP and low BMI were observed in 51 (38.6%) and 47 (35.6%) participants, respectively. Primary amenorrhea in 3 participants (2.3%) and 29 (22.1%) reported experiencing secondary amenorrhea; they had lower BFP than the dancers who did not experience amenorrhea (P = .041, 95% CI, -2.51 to -0.05). Conclusion: Female elite adolescent dancers in China may have lower BFP and menstrual problems. Given that lower BFP may contribute to the occurrence of menstruation disorders, it is essential to pay an attention to both BFP and the menstruation status in female elite adolescent dancers.

Introduction: The grand jeté requires grace and proper biomechanics to produce the iconic glide through the air. Understanding how the preceding choreographed movements affect take-off and flight may influence teaching and training. We sought to examine the effects of 5 common preparatory approaches on grand jeté biomechanics. Methods: One male and 19 female dancers (19.3 ± 1.4 years; 1.61 ± 0.05 m; 58.1 ± 7.3 kg) with 12.5 ± 4.8 years of formal ballet experience performed grand jetés from run, chaine, chasse, assemble, and step-step approaches. Plié angle (deg), vGRF (BW), leap height (m), and leap distance (m) were measured with a motion analysis system and a force plate. One-way repeated measures ANOVAs were conducted to compare variables between approaches and Bonferroni tests were used for pairwise comparisons. Results: Plié depth, vGRF, leap height, and leap distance were all significantly different (P < .001). Plié angles (43.6-68.2 deg) were deepest for the assemble and shallowest for the run. vGRF (2.46-3.81 BW) were greatest for the assemble versus all but the run, and smallest for the chaine. Leap height (0.33-0.41 m) was highest for the run versus the chaine and step-step, but not versus assemble. Height was lowest for the chaine. Leap distance (0.24-1.03 m) was longest for the run and shortest for the assemble. Conclusions: The run approach optimizes the float through the air illusion (high leap height and distance) through applying high vGRF but moderate plié angles. The chasse approach is the next most optimal. The 2-legged assemble requires deeper plié angles to achieve height but produces shorter horizontal distances. Single leg plié training may enhance grand jeté performance and reduce injury risk from approaches such as the run, chaine, chasse, and step-step.Level of Evidence: Level 2.

Objective: To explore perspectives and experiences of adolescent ballet dancers in Australia in relation to dance-related injuries and their impact, injury risk factors, prevention, and treatment. Design: Adolescent ballet dancers aged from 12 to 19 years in Australia were invited to participate in an online qualitative survey. Methods: Responses to open-ended questions were analyzed thematically using grounded theory while quantitative information was summarized with descriptive statistics and triangulated with qualitative data. Results: Nineteen adolescent dancers reported experiencing pain and multiple injuries but hiding or ignoring injuries due to fear. Dancers recognized the significant physical and psycho-social impact of dance-related injuries on themselves and others. Several risks and injury prevention strategies were identified by dancers. Dancers perceived that treatments were not always informed or effective. Conclusion: Findings suggest that adolescent ballet dancers experience multiple dance-related injuries but require support to disclose injuries, participate in injury prevention, and access treatment. Health professionals may improve quality of care by increasing their understanding of ballet and providing specific management advice. Dance teachers may benefit from further education to support their students. Clinical trials are required to confirm or negate the validity of proposed injury risks and the effectiveness of injury prevention strategies and treatments.