Journal of Dance Medicine & Science最新文献

Introduction: Sesamoid bones absorb and disperse weight from the metatarsal bones. Sesamoid injuries occur primarily in dancers and runners, with nonoperative management as the first line of treatment. Due to the lack of secondary blood supply, the sesamoids are at risk for osteonecrosis and nonunion fractures. The literature supporting orthobiologics for the treatment of sesamoid injuries is limited. Methods: In this case, a 28-year-old female dancer with sesamoid osteonecrosis underwent a leukocyte-rich platelet-rich plasma (LR-PRP) injection to the fibular sesamoid. Results: The patient reported significant improvement in pain at the 2-month follow-up and returned to regular auditions at the 3-month follow-up. At 2-year follow-up, the patient's symptoms returned to baseline. Conclusion: This is the first known case of sesamoid osteonecrosis treated with LR-PRP. LR-PRP should be considered in the treatment of sesamoid osteonecrosis in those who show limited improvement with standard conservative measures.

Introduction: Contemporary concussion literature has yet to establish appropriate clinical management guidelines to address the unique needs of performing arts populations, especially at the collegiate level. Therefore, the purpose of this investigation was to collate current evidence regarding post-concussion return to performance management among university-aged performing artists to generate broad clinical implications.

Methods: The research team was comprised of two faculty members in the performing arts, one concussion researcher, and athletic trainer, two university librarians, and one physical therapy graduate student with expertise in post-concussion management among performing arts patients. Two librarians searched the literature using PubMed, Cochrane, SPORTdiscus, and Education Research Complete. Studies were eligible for preliminary inclusion if they were written in English, conducted in the United States, as well as published in a peer-reviewed journal. There were no restrictions on publication date due to the limited literature on this topic. The most recent search was conducted in July 2023.

Results: Of the 18 studies identified during the search process, only 2 met the inclusion criteria. Broadly, this investigation identified common mechanisms of injury among stage crew/technicians and dancers who are of university-age. Furthermore, both studies identified several patients who opted to return to performing arts on their own volition. However, there were no studies that solely focused on the collegiate performing arts population and their return to performance procedures.

Conclusions: Overall, these findings highlight a momentous gap in concussion literature regarding how to guide clinicians and academic teams when returning collegiate performing artists back to their performance environment(s). Thus, additional research is strongly warranted to understand the lived experiences of performing artists with concussion, as well as how to address specific coursework-related demands to support their recovery.

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.

Introduction: The primary aim of this study was to present descriptive heart rate (HR), heart rate recovery (HRR) and RPE data for the DAFT and HIDT within one sample of contemporary dance students. The second aim was to explore if objective (HR) and subjective (RPE) data were correlated between tests.

Method: 40 (11 males, 29 females) university dance students with a mean age of 18.8 ± 1.8 years performed the DAFT and HIDT on 2 separate occasions within 1 week. Measurements were HR after 4 minutes in all stages of the DAFT, the percentage of age-predicted maximal HR (%HR_max) of all stages of the DAFT and at the end of the HIDT, and peak HR (HR_peak) at the end of both tests. Subjective ratings of perceived exertion (RPE) and HR recovery after 1 minute of rest (HRR) were determined after the tests.

Results: HR_peak of the DAFT and HIDT were 188.1 ± 11.0 and 185.3 ± 7.3 beats·min^-1, respectively. There were high positive correlations between HR_peak of the HIDT and stages 3 to 5 of the DAFT (r = 0.716-0.740, all P-values < .01). HRR (r = .678, P < .01) and %HR_max (r = .746, P < .01) showed moderate to high correlations between the DAFT and HIDT. The anaerobic training zone was reached in stages 4 and 5 of the DAFT and at the end of the HIDT. The subjective RPE scores did not significantly correlate between DAFT and HIDT, neither with objective HR data.

Conclusion: Although the DAFT and HIDT differ in intensity and work-to-rest ratio, there were high correlations between HR and HRR data of both tests and both tests reached intensities above the anaerobic threshold (%HR_max > 85%).

Purpose: The Backalast^® compression jacket is intended to improve posture and proprioception of the trunk and shoulder girdle for dancers and dance students during dance training by way of elastic bands in the rear of the garment (which include bands enclosing the inferior thorax). This study was intended to investigate whether there is evidence to support those objectives. Materials and Methods: Fifteen dance students participated (4 male, mean age 19.9 ± 1.4 years old). The dependent variables of trunk-pelvis angle and proximity of trunk axis to global vertical for each participant were measured using optical motion capture before and after the completion of a series of trunk movements. The Helen Hayes model, which we used to represent the trunk, includes the shoulder girdles as part of the trunk. We compared the effect of the type of garment (Backalast^® or control compression shirt) worn upon the 2 dependent variables, within-subject with paired t-tests. The order of whether Backalast^® or control compression shirt was worn first was alternated between participants. Results: The pre/posttest difference in trunk proprioception as represented by the construct of ability to reproduce trunk-pelvis angle wearing the Backalast^® was 0.8° ± 0.8°, but for the control shirt, the difference was 1.8° ± 1.4°, P = .03. The difference between garments in vertical trunk alignment, measured after the series of trunk movements, was not significant. Conclusion: Our findings suggest that the Backalast^® can help enhance trunk proprioception when compared to the control compression shirt, although it did not change the angle at which the participants' held their trunks while standing erect (proximity to global vertical).

Introduction: Dance is physically demanding and results in blood lactate (BL) accumulation and elevated Heart Rate (HR). Researchers recommend using either Active Recovery (AR; eg, low-to-moderate intensity-exercise) or Passive Recovery (PR; eg, complete rest) modes after activity. We compared BL and HR responses between AR or PR over a 15-minute recovery period following a Kathak dance. Methods: Twelve female dancers (31.0 ± 6.0 years; 161.5 ± 4.9 cm; 55.5 ± 5.8 kg) performed 2 dance testing sessions (Day 1 = AR, Day 2 = PR) 48 hours apart. Each session started with a 10-minute warm up followed by dancers performing four 2-minute stages of Kathak dance, with three 1-minute periods between stages where we recorded HR and their Rate of Perceived Exertion (RPE:scale = 6-20) to match the intensity of both sessions. Post-dance, we recorded dancers' BL and HR at 1, 3, 5, 10, and 15 minutes while they recovered via AR or PR. Separate 2(mode) × (time) Repeated-Measures-ANOVA followed by simple-main-effects testing and adjusted Bonferroni-pairwise-comparisons examined differences in BL and HR responses across modes and time(α = .05). Results: Dancers' HR and RPE were similar across sessions. No mode × time interaction existed in BL (F_4,8 = 3.6, P = .06). BL levels were similar across modes (F_1,2 = 0.5, P = .5). BL levels reduced over time (F_4,8 = 6.0, P = .02), but Bonferroni-comparisons did not reveal any pairwise differences. In HR a significant mode*time interaction (F_4,36 = 11.0, P = .01, η² = .55) was observed. Both Active and Passive recovery modes achieved absolute HR levels by 15 minutes, with PR mode stabilizing within 5 minutes. Conclusions: Over a 15-minute recovery period after Kathak dance, dancers' BL and HR responses were similar across time in both AR and PR, with HR being higher in AR. Dancers' HR remained similar from 1 to 3 minute post dance recovery and then dropped over time. Thus, dancers can rest up to 3 minutes and still maintain the same elevated HR. Overall, dancers can choose either AR or PR as their recovery mode based on their individual preferences.

Background: Young athletes are thought to be models of peak physical condition, capable of exceptional physical accomplishments. However approximately 64 UK athletes aged 12 to 35 will die each year from a phenomenon known as Sudden Cardiac Death (SCD). SCD can be defined as an unexpected death as a result of abrupt loss of cardiac function within an hour of symptom onset. Undiagnosed heart conditions such as arrhythmias are often found to be the cause of SCD. Advantageous physical attributes found in athletes' hearts can complicate diagnoses as hearts with inherited conditions can appear physiologically similar to hearts adapted to strenuous exercise. Growing research surrounding SCD within sporting populations aims to decrease mortality rates however there is an absence of study specifically into SCD in dance. Within sport, the topic of cardiac screening has generated widespread controversy which is fueled by a lack of empirical evidence. There is currently no international consensus of pre participation cardiac screening methods within dance or sport, potentially leaving many dancers and athletes at risk. Methods: As part of this study, existing material surrounding the topics of SCD and cardiac screening in athletes and dancers was gathered. All existing studies at the time of writing in relation to cardiac screening in athletes and dancers were collected and analysed in order to compare results and evaluate the methodological limitations.This process aimed to identify gaps in current knowledge and research to inform future study. Results: This article aimed to analyze the epidemiology of SCD within sport and dance and to make recommendations for pre-participation screening within dance institutions. The study highlights the need to increase awareness of SCD within the dance community and determine appropriate screening approaches depending on context and setting.