Journal of Dance Medicine & Science最新文献

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.

Introduction: The aim of this study was to analyze perceptions of strength training in vocational circus and dance students. It was hypothesized that due to the higher relative strength demands and associated risks of working at height in some aerial and acrobatic disciplines that circus students would be more open to strength training than dancers. Methods: Eighty students completed the Training Information Survey (TIS) (Mean age = 20.74 ± 2.71); 39 circus students and 41 dance students. 97% of circus students and 69% of dance participants reported that strength training was a required part of their training with students participating in strength training 4.24 ± 0.98 and 3.05 ± 1.42 day per week respectively. Results: Perceptions of strength training amongst vocational circus and dance students appear to be favorable, with both sets of students strongly agreeing with the statements "Strength training is essential to my overall development as a dancer/circus artist" (5.00 (IQR 1.00) and 5.00 (IQR 1.00) respectively). Following Bonferonni correction only one statement returned statistically significant results with dance students agreeing more strongly with the statement "Strength training increases muscle size," U = 473.00, P = .001. Students also agreed that strength training helped them to feel better mentally and physically, that strength training is beneficial for both men and women and that it should not be designated as specific to either sex. Conclusion: Results support earlier studies that suggest a cultural shift in perceptions of strength training and ideal esthetic in dance, particularly amongst students and that they are keen to incorporate strength training into their practice. Educational establishments should note students' interest in participating in strength training, reviewing how to embed effective strength training education, more coaching and time allowance for these activities within their timetable. Further research with a greater sample size is recommended to further substantiate these indications of a shift in perceptions.

Introduction: Dancing en pointe requires ballet dancers to stand on the tips of their toes while wearing a structured pointe shoe. Understanding the effect of pointe shoes on ballet dancers' biomechanics, function, symptoms and skin health is essential to guide shoe development and ultimately improve dancer performance. Therefore, the purpose of this scoping review was to map the evidence and identify knowledge gaps related to the effect of wearing pointe shoes on professional and recreational ballet dancers. Method: A scoping review was conducted by searching 6 electronic databases and the International Association for Dance Medicine and Science Bibliography. Results: Thirty-five studies were grouped into 5 categories: pointe shoe factors (eg, toe box and shank, pointe shoe status; 9 studies), shoe types (eg, flat shoes vs demi pointe vs pointe; 10 studies), ballet movements (11 studies), symptoms (5 studies), and intrinsic dancer factors (eg, foot type/toe length; 7 studies). Studies were published between 1979 and 2023, with 72% (n = 23) published between 2006 and 2020. Most (86%) of the studies were cross-sectional. Most studies explored biomechanical outcomes and the most common data collection device was force plates (19 studies). Overall, there was an insufficient volume of evidence for specific research aims. Significant gaps in knowledge exist regarding functional and performance-based outcomes, injury outcomes including exploration of factors such as shoe age/usage, and pointe shoe treatment factors. Conclusions: Currently the field of research suffers from threats to ecological validity, with many study methods not reflecting ballet-specific demands or environments. The impact of pointe shoes on ballet dancers is a developing research area, and this scoping review can help guide future research decisions. Studies need to target the knowledge gaps and employ rigorous ecologically valid study designs and ensure that findings inform shoe design and dancer education to minimize injury and maximize comfort and performance.

Introduction: It has been recognized that practicing ballet could strengthen the leg muscles, improve balance, and reduce fall risk. However, few studies have investigated how ballet practice alters a person's gait pattern, and this knowledge gap could present a barrier to designing ballet-based training programs. This study examined dynamic gait stability and spatiotemporal gait parameters among professional ballet dancers during normal level overground walking. Methods: Twenty young adults were recruited: 10 ballet dancers (24.5 ± 4.9 years) and 10 age- and sex-matched non-dancers (22.6 ± 3.4 years). Participants walked on a 10 m linear walkway at their self-selected speed. Dynamic gait stability and common gait parameters (step length, step width, gait speed, and cadence) were determined from the collected kinematic data and compared between groups with a significance level of .05. Results: The results showed that both groups displayed comparable dynamic gait stability at touchdown (P = .140) and liftoff (P = .638). However, ballet dancers walked with a longer (P = .054), narrower (P = .009), and faster step (P = .014) at a marginally quicker speed (P = .063) than non-dancers. Conclusion: Our study suggests that young professional ballet dancers have different gait patterns, but similar dynamic gait stability compared to non-dancers. These findings not only provide insight into the mechanisms of dynamic stability control among young ballet dancers during gait but expand our understanding of the control of dynamic gait balance of human locomotion across a wide variety of populations and walking conditions.

Introduction: The importance and potential benefits of muscular strength in the adolescent's development for health and fitness has been demonstrated in the literature. Maximal muscular strength and its assessment, however, is not a primary assessment criterium in the selection of young talented dancers.

Methods: The present study evaluated the within- and between session reliability, variability, and minimal detectable change (MDC) of the isometric mid-thigh pull (IMTP). Thirty-five participants (female n = 17) participated in 2 identical assessments on the same day with 4-hour break in between. Three 3-second IMTP were performed, and the mean peak force value was used for the analyses.

Results: Within-session the ICC indicated excellent reliability (ICC = .99, 95% CI: 0.98-0.99). Between-session reliability was excellent (ICC = .98, 95% CI: 0.95-0.99). The standard error of measurement was 4% (48 N), the minimum detectable change was 12% (134 N) and the CV was 3%. There were no within-session statistically significant differences, but statistically significant differences between-session were observed (P < .001). Limits of agreement ranged from -121 N (95% CI -186 to -56 N) to 307 N (95% CI 243-372 N).

Conclusion: The observed results demonstrated excellent within- and between sessions reliability, low variability, and an MDC of 12%. The consistency of the within-session scores suggest that peak force data may be obtained with single try efforts. The statistically significant difference in the means of the retest session, however, suggests that the time of the day or the time since entrained awakening may be affecting performance in adolescent dancers. The results of the current study indicate that the IMTP is a reliable assessment tool for maximal muscular strength in adolescent dancers.

Background: DanceSport is a variant of Ballroom dancing, a style that is performed as a couple dancing together. Although there are many participants worldwide, the amount of research on injuries done in this style of dancing is limited.

Objective: The aim of this study was obtaining information about the DanceSport Athletes in the Netherlands including anthropometrics, level, frequency and duration of dance training per week. Our second objective was to investigate injury prevalence and type of injuries.

Study design: Retrospective questionnaire study.

Methods: All 816 registered active dancers within the Dutch DanceSport Association received an online questionnaire with questions on anthropometrics, level of dancing, frequency and duration of dance training, and questions on injuries. The Chi-Square test was used to calculate differences between categorical variables.

Results: A total of 218 dancers (33.7%) completed the questionnaire, 107 males (49.1%), and 111 females (50.9%). The mean age for men was 42 ± 15.9 and 36 ± 15.1 for women. 176 dancers (80.7%) reported 1 or more injuries. Foot, ankle, and lower leg injuries were reported most frequently, 49 males (45.8%), and 60 females (54.1%). No significant difference was found in the total number of injuries for the variables sex (P = .761) and discipline (P = .225). Significantly more head and neck injuries were identified in female Standard dancers (P < .001) compared to male dancers. Also, Standard dancers have more back injuries compared to dancers in both disciplines (P < .009).

Conclusion: With the described anthropometrics and an 80% lifetime prevalence of injuries, this group can be compared to other dance forms. Significant differences in injuries of the head and neck for female Standard dancers compared to male dancers and significantly more back injuries in Standard dancers compared to dancers in both disciplines were found. Future studies need to translate and validate existing questionnaires in Dutch for use in this population.

Introduction: Dancers have self-reported a link between spinal extension movements and low back pain (LBP). Researchers have not reported the total number or frequency that spinal movements occur in ballet, modern, or hip-hop dance classes or performances. The purpose of this study was to report the number of spinal movements dancers are exposed to in different dance environments.

Materials and methods: We analyzed 65 dance videos on YouTube.com for dance movements within 7 dance environments: ballet class and performance, modern class and performance, and hip-hop breaking, ciphers (large groups), and battles ("1v1s"). Two reviewers recorded counts of spinal (spinal flexion, extension, lateral flexion, and rotation), impact (jumps, leaps, and falls), and partnering movements (lifts, catches, and leans). Data analyses were processed in Jamovi (the jamovi project, Sydney, Australia). We reported movement totals, percentages, frequency, ranges, means with standard deviations (SD), and medians with interquartile range (IQR). We calculated significant differences using Mann-Whitney U tests.

Results: Video length ranged from 3 to 141 minutes (mean ± SD: 38.4 ± 38.3, range: 138). the average spinal extension movements ranged from 2 ± 0.8 to 7 ± 9.6 movements per minute across genres. Modern dance class had the most spinal flexion (89 ± 53.6), rotation (60 ± 40.8), and lateral flexion (74 ± 20.7) movements. Ballet performance had the most spinal extension movements (77 ± 69.8), jumps (74 ± 48), and leaps (19 ± 18.2). Hip-hop breaking had the highest number of falling movements (2 ± 2.3). Partnering movements were only present in ballet performance, modern dance performance, and hip-hop breaking environments.

Conclusions: Movements that increase LBP occur often in all 3 dance genres. Dancers can expect frequent exposure to spinal extension movements; therefore, we recommend strengthening back and core musculature for all dancers. We recommend that ballet dancers also strengthen their lower extremity muscles. For modern dancers, we recommend strengthening their obliques. For hip-hop dancers, we recommend increasing muscular power and muscular endurance.