Journal of Dance Medicine & Science最新文献

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.

Introduction: Ankle sprains are among the most common injuries in dancers. Following one or more severe sprains, some individuals will experience residual mechanical and functional deficits, otherwise known as chronic ankle instability (CAI). Dancers who suffer from CAI may have weaker musculature surrounding the ankle and altered landing mechanics. The purpose of this study was to compare ankle strength and saut de chat landing mechanics between dancers with and without CAI.

Methods: Dancers with and without CAI, defined by the Identification of Functional Ankle Instability (IdFAI), participated in the study (CAI n = 8; IdFAI = 18.75 ± 5.50 points; age = 20 ± 1.5 years; training = 15.5 ± 3.5 years) (Control n = 8; IdFAI = 7.13 ± 3.40 points; age = 19 ± 0.6 years; training = 15.9 ± 2.5 years). Strength and leap landing mechanics were measured on the affected ankle for the CAI group and on the preferred landing leg of a leap for the control group. Concentric and eccentric ankle plantar flexion, and subtalar inversion and eversion strength were determined with dynamometry set at an angular velocity of 60°•s^-1. Force plates and motion capture cameras were used to calculate lower extremity kinematic and kinetic data as participants performed 3 saut de chat leaps. Independent t-tests were calculated to determine differences between groups.

Results: Compared to dancers without CAI, dancers with CAI had lower eccentric plantar flexor strength, landed with higher vertical ground reaction forces, and absorbed greater power at the knee-joint during landing.

Conclusion: Whether dancers who are weaker are more prone to injury or ankle-joint injury leads to muscular weakness is unknown. Dancers with CAI appear to lack control during leap landing while concomitantly shifting loads proximally away from the ankle-joint. We encourage dancers with and without CAI to engage in additional training that enhances ankle strength.

Introduction: Studies showed that professional dance is often associated with a high degree of acute musculoskeletal injuries. These injuries' etiology predominantly describes their biomechanical or other extrinsic factors, but there is a limited number of scientific reports dealing with the perceived stress or mental health status concerning the physical complaints especially, among Hungarian professional dancers. Materials and Methods: In this study, we used validated questionnaires (RESTQ, SEFIP, Mental Health Test) filled out by Hungarian professional female dancers (N = 168) via an online platform anonymously and analyzed statistically. Results: Our findings showed a significantly positive relationship between musculoskeletal complaints and perceived stress, an elevated level of general stress, and a higher level of resilience in this population compared to the general population. Conclusion: Dancers demonstrate a heightened perception of stress; however, they exhibit elevated scores on resilience assessments, indicative of heightened functionality in their daily lives. Stress, per se, may not be directly regarded as a causative factor for acute musculoskeletal conditions, but it could potentially influence the severity of pain sensations and subjective pain levels in the context of existing injuries. Additional investigations are warranted to elucidate the precise mechanisms by which stress exacerbates the pain experience among dancers.

Introduction: En pointe, in which weight is placed on the tiptoes, is a fundamental practice for female ballet dancers with pointe shoes. The center of mass (COM) is maintained over the base of support and the relative position of COM to the center of pressure (COP) is especially important when conducting a pirouette in ballet. A pirouette is a fundamental turn in classical ballet with flat shoes and pointe shoes. The investigation of the turn with pointe shoes would be favorable for understanding the movement with limited base of support. Herein, we aimed to determine the differences in the ability to perform pirouettes with pointe shoes between professional and amateur ballet dancers. Methods: This study included 8 professional and 9 amateur ballet dancers. The dancers performed a single pirouette, and the movement was captured and analyzed in 3 phases: turning with double-leg support (TDS), turning with single-leg support in pre-swing (TSSp), and turning with single-leg support in mid-swing (TSSm). The analysis focused on the inclination between the vertical angle and the COP-COM line, the vertical maximum reaction force, and the jump-up time in each phase. Results: The results showed no significant differences between the TDS and TSSp. However, professional ballet dancers exhibited significantly lesser posterior inclinations (professional; 2.05° ± 0.90°, amateur; 3.88° ± 1.67°) and jump-up time (professional; 0%, amateur; 1.4% ± 1.3%) than amateur dancers during TSSm. Conclusion: Overall, the findings suggest that professional dancers exhibit superior control skills regarding the COP-COM line than amateur dancers during TSSm. These results may be attributed to the fact that professional dancers can maintain the COM as close to the upright as on the COP without jumping during TSSm. This enables professional dancers to conduct the movements esthetically and continue on to the other movements in the dance phase.

Background: Periacetabular Osteotomy (PAO) is a well-established surgical intervention for the treatment of hip dysplasia. Purpose: Our primary objective was to assess whether a group of young flexibility athletes who underwent PAO for hip dysplasia recovered their pre-operative hip range of motion (ROM) within 1 year of surgery. Our secondary objective was to compare hip ROM recovery between a group of young flexibility athletes and a group of non-flexibility athletes who underwent PAO for hip dysplasia. Results: In our study, 100% of flexibility athletes regained preoperative hip external rotation at 1-year post-operation. This was also the first plane of motion to return to preoperative motion in flexibility athletes. A significantly higher percentage of non-flexibility athletes regained their preoperative hip internal rotation compared to flexibility athletes (100% compared to 54%; P = .02), but not flexion or external rotation at 1-year post-operation. Conclusion: Our findings may help providers to set expectations regarding the recovery of hip ROM in flexibility athletes who undergo PAO for hip dysplasia.Level of Evidence: Level IV.