Female Dancers Research Articles

Poster 117: Dancers Following Primary Hip Arthroscopy Demonstrate Favorable Outcomes and High Rate of Return to Dance at a Minimum 5-Year Follow-Up

Objectives: The purpose is to report minimum 5-year follow-up patient-reported outcome measurement scores (PROMS) and return to dance in dancers who underwent primary hip arthroscopy, and to identify predictors for secondary surgeries Methods: Prospectively collected data from May 2010 and June 2016 was retrospectively reviewed. Patients were included if they participated in dance one year prior to surgery at any level, had preoperative and minimum 5-year follow-up scores for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score–Sports Specific Subscale (HOS-SSS), and Visual Analog Scale for pain (VAS). Exclusion criteria were previous hip conditions, previous ipsilateral hip surgery, Tönnis grade > 1, or lateral center-edge angle < 18°. The minimal clinically important difference (MCID), patient acceptable symptomatic state (PASS), and the maximum outcome improvement (MOI) were reported. A logistic regression model was used to identify predictors of secondary surgeries. Results: Fifty-one hips (48 female dancers) were included. The average age and follow-up were 29.8 ± 17.2 years and 79.1 ± 23.2 months, respectively. Improvement in all PROMS (P < 0.001) was reported. Achievement rates of MCID for the mHHS, NAHS and VAS were 83.3%, 85.7% and 85.7%, respectively. Achievement rates of PASS for the mHHS and the International Hip Outcome Tool–12 were 90.5% and 81%, respectively. The MOI was 73.8% for the mHHS, and 78.6% for the NAHS. Six dancers (14.3%) underwent revision hip arthroscopy and three dancers (5.8%) converted to total hip arthroplasty. The rate to return to dance was 79.1%. Femoral head Outerbridge grade was identified as a predictor for secondary surgeries [P = 0.045, odds ratio 6.752, 95% CI [1.043 – 43.688]). Conclusions: Dancers following primary hip arthroscopy experienced significant improvement in all PROMS and achieved high rates of the MCID, PASS, and MOI at a minimum 5-year follow-up. Further, 89.3% continued to dance with 68% returning to the pre-injury or higher performance level. Femoral head Outerbridge grade was found to be a predictor for secondary surgeries.

Excessive Femoral Anteversion Leading to Symptomatic Posterior Femoroacetabular Impingement, Cam Deformity of the Posterior Femoral Head-Neck Junction, and Anterior Hip Instability in a Dancer: A Case Report.

An adolescent female dancer with excessive femoral anteversion presented with posterior and anterior hip pain aggravated by poses that required extension and external rotation. Imaging revealed an atypical cam deformity of the posterior head-neck junction. During surgery, the posterior head-neck junction was observed to impinge on the posterior acetabulum with anterior subluxation of the hip. After a derotational femoral osteotomy, the patient experienced resolution of her symptoms. Excessive femoral anteversion can lead to reactive cam deformity, posterior intra-articular impingement, and anterior hip instability in patients who require repetitive hip extension and external rotation, such as ballet dancers.

Developing the Temporal and Order Characteristics of a Dance-Specific Star Excursion Balance Test (dsSEBT).

Previous studies have made crucial steps toward developing a dance-specific balance test to challenge dancer's balance capabilities wherein positional characteristics, timing, as well as reach order were altered. However, the authentic performance nature of the protocols could be questioned. The aim of this study was to examine the effects of different tempo and order variations on the previously developed Dance-Specific Star Excursion Balance Test (dsSEBT). Twenty- two female dancers voluntarily took part in the research (162.68 ± 6.57 cm; 61.35 ± 11.25 kg). This research looked at 3 different temporal variations as well as an alternate reach order, to the traditional order, to examine the effect it may have on individual spoke scores. Reach distances (% of limb length), center of pressure (cm2), and error scores were measured. Overall, the varying tempos did not create a significant change in any of the variables measured (P = .067-1.00) which suggests that dancers have a unique ability to adapt to temporal changes due to the nature of ever-changing tempos in class and performance. Additionally, the new reach order did not affect the difficulty level of each individual spoke, which agrees with previous research suggesting that the crossed side and crossed front spokes are in fact the most challenging spokes for ballet and contemporary dancers to accomplish. Results support the utilization of all 8 spokes of the dsSEBT in identifying balance deficits in this genre of dancers. The data collected in this study provides useful baseline measurements to further develop a reliable dance-specific dynamic balance test protocol to be used by ballet and contemporary dancers.

Impact of Mindfulness-Based Psychoeducation Program on Performance Anxiety among Indian Classical Dancers

Performance anxiety refers to the high levels of anxiety faced by performing artists, experienced psychologically, physiologically, or behaviorally, which reduces the quality of their performance and causes immense stress. Using various techniques of mindfulness, such as the body scan and psycho-education, to bring awareness to thoughts, beliefs, and emotions has been suggested in previous studies as an effective way to reduce performance anxiety. The purpose of this paper was to examine the impact of mindfulness-based psychoeducation on performance anxiety among female Indian Classical Dancers. Nine female Indian classical dancers aged 18-25 years were included in the study. All the participants filled out the Performance Anxiety Inventory (PAI), attended the mindfulness-based psychoeducation sessions, and after a week, filled out the PAI after the intervention. The findings of the study indicated statistically significant differences between the pre-intervention and post-intervention scores of the participants, indicating a reduction in the level of performance anxiety of the participants after the intervention.

“Dancer as collaborator, co-author, co-owner, co-creator: power relations between dancer and choreographer”

ABSTRACT In contemporary concert dance, the efforts and creative powers of dancers can be overlooked and devalued against those of the choreographer. Might a binary relationship between the mind and the body haunt the relationship between the choreographer and dancer with the looming specter of a female body that is obedient, fertile, and shaped? This article explores whether dancers in contemporary concert dance should be credited in the choreographic process, creation of a technique, and in performance when they have actively contributed to the creative process. Weaving in my autoethnography examining my experiences as a dancer and choreographer in New York City, this article explores different models of working and creating engaging with the scholarship of dance practitioners and philosophy, dance, and feminist scholars. Seeing through a Marxist and Feminist lens, power relations are examined between choreographers and dancers, unraveling how these relations result in who is credited and whose labor and precarity is recognized. The trope of dancers, specifically female dancers, being mere instruments or muses is deconstructed in the re-examination of the relationship between modern dance pioneers Lester Horton and Bella Lewitzky.

Injuries in Ballroom DanceSport: A Retrospective Study on Prevalence and Relation With Demographic Data.

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. 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. Retrospective questionnaire study. 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. 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). 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.

Analysis of Serum Ferritin Levels in a Group of Elite Ballet Dancers.

Iron plays a significant role in energy production. However, it is not uncommon for athletes to be diagnosed with iron deficiency (ID), suggesting a correlation between performance and iron regulation. As a result, the International Olympic Committee has recommended iron screenings during health evaluations for elite athletes. Furthermore, athletes participating in esthetic sports are at increased risk for suboptimal iron intake due to disordered eating. Therefore, the purpose of this study was to investigate the distribution of serum ferritin (SF) in a cohort of elite ballet dancers and determine associations between vitamin D, anthropometric measures, stress injury, and dietary preferences. Electronic health records of 40 elite ballet dancers (22 female, 18 male), age 19 to 38 years old, from the 2020 to 2021 pre-participation physical screening were examined. Chi squared comparisons were calculated to evaluate the association between SF and additional variables (ie, gender, age, height, weight, body mass index, vitamin D, stress injury history, and dietary preferences). SF values were compared to published normal and athletic population data. 58.97% of participants displayed normal or above SF values (>50 ng/ml), while 41.02% displayed minimal (<50 ng/ml) to depleted (<0.12/ng/ml) SF values. Approximately, 68% of the female dancers were ID and did not meet the minimal value needed for athletes. Females were more likely to have lower SF distributions (x2 [4] = 15.6377, P = .004) compared to male dancers. Additionally, dancers who reported dietary preferences (ie, vegetarian) were more likely to display lower SF distributions (x2[4] = 13.3366, P = .010). Over half of the female elite ballet dancers were ID which is consistent with current research. Females were at a significant higher risk compared to male dancers who reported dietary preferences. These findings suggest iron screenings should be considered in elite dancer populations.

Adolescent Dance Team Fitness: Initial Quantitative Normative Values.

Research on improving dancer fitness to enhance performance capacity and prevent injury continues to grow. Fitness research for the adolescent dance team population, however, presents an evidence void. Utilizing studio-based assessments, this descriptive quantitative study reveals an initial set of fitness normative values for the female adolescent competitive dance team dancer population. 115 female dance team dancers ages 12 to 17 participated in a 90-minute field test assessment battery for cardiorespiratory fitness, muscle endurance of the upper body, lower body, and core, and lower extremity power. Descriptive statistics (mean, standard deviation, and interquartile range) created an initial set of quantitative fitness normative values for this population. Dancers' results revealed 29.5mL/O2×min ± 5.7 estimated VO2max, 35 ± 16 push ups, 62 ± 14 half sit ups, 51 ± 13 squats in 1 minute, 190 ± 23 cm broad jump, 445 ± 65 cm right lower extremity triple hop, and 450 ± 69 cm/left lower extremity triple hop. Discussion includes comparison of findings relative to previously established adolescent fitness and dancer normative data. Discussion also suggests implications, study limitations, and future research directions.

Body dissatisfaction, ideals, and identity in the development of disordered eating among adolescent ballet dancers.

Little is known about how female adolescent ballet dancers-a group at high-risk for the development of body dissatisfaction and eating disorders-construct body ideals, and how their social identities interact with body ideals to confer risk for disordered eating. Using a novel body figure behavioral task, this study investigated (1) whether degree of body dissatisfaction corresponded to severity of disordered eating thoughts and behaviors, and (2) how ballet identity corresponded with ideal body figure size among adolescent ballet dancers. Participants were 188 female ballet dancers ages 13-18 years who completed self-report measures of study constructs and the behavioral task. Linear regression models indicated that more severe body dissatisfaction was positively associated with increased disordered eating thoughts and behaviors (p < .19), except for muscle building (p = .32). We also found that identifying more strongly as a ballet dancer was correlated with having a smaller ideal body size (p = .017). Findings from this study suggest desire to achieve smaller body sizes is correlated with more severe disordered eating endorsement and stronger ballet identity. Instructors and clinicians may consider assessing the extent to which individuals identify as a ballet dancer as a risk factor for disordered eating and encourage adolescent dancers to build and nurture other identities beyond ballet. Eating disorders are debilitating conditions that can lead to malnutrition, social isolation, and even premature death. Though disordered eating thoughts and behaviors can affect anyone, adolescents in physically demanding and body image-driven activities including ballet dance are particularly vulnerable. Investigating how factors like body dissatisfaction and strength of identity are associated with disordered eating among high-risk groups is crucial for developing effective prevention and intervention methods that minimize harm.

The overlooked contributions of African American women hip hop dancers to breaking and hip hop culture

In the late 1980s through 1990s shifts within the aesthetic of hip hop culture helped the sustainability of breaking. When the discussion of hip hop and its major contributors are mentioned, seldom is there any acknowledgement of African American women. Like many art forms, hip hop is male-dominated, which can eclipse narratives about African American women in early hip hop dance circles. African American women practitioners are rarely called upon to moderate panels, write or are acknowledged as true pioneers of the field. Many times, throughout hip hop, African American women kept the dance alive with their resiliency, becoming the catalyst from the streets that help preserve and continue its legacy. The question I ask is: How have these African American women impacted global hip hop culture and why are they unknown to us? The article will examine performance qualities within interdisciplinary practices that forged ahead hip hop culture with these under-represented New York hip hop female dancers. Insights about the experience of these African American female pioneers bring into light historical concerns of exploitation and representation right in time for the introduction of breaking in the 2024 Olympics.

Kerala Kalamandalam: A legacy revisited

The performance landscape of Kerala is diverse, and its history hails the glory of Kutiyattam, the sole surviving Sanskrit theatre tradition in India; Kathakali, the classical dance-drama; and Mohiniyattam, an exclusive female dance form. This is in addition to a huge variety of ritual and folk performance forms all over the region. While the first onstage recital of Kutiyattam performance and the subsequent development of its aesthetics and criticism date back to tenth and eleventh century AD, the entire Kathakali repertory originated and developed in the seventeenth century. On the other hand, Mohiniyattam seems to have originated even later. As a residential training centre for traditional performing arts in Kerala, Kalamandalam facilitated intense and uninterrupted communications amongst the top-ranking artists of various art forms. The Second World War had its devastating effects on the cultural institutions in India in general, and Kalamandalam in particular. Then, the Department of Education, Government of India, took over the administration of Kalamandalam. In 1976, Kalamandalam became a grant-in-aid institution under the Charities Registration Act and started functioning under a General Council and Executive Board constituted by the Government of Kerala. In 2006, Kalamandalam was deemed to be a university, functioning under the Cultural Affairs Department, Government of Kerala. The main objective of the institutional transformation was to combine practical training in different performing arts at the academic level. Several groups of students are now coming out of Kalamandalam every year after successfully completing their graduate and postgraduate programmes. Advanced training programmes are held at the Nila Campus in Cheruthuruthy, while the undergraduate courses are offered at the sprawling Vallathol Nagar Campus.

PAJAGA BONE BALLA DANCE AS ETHNO PEDAGOGY IN LUWU SOCIETY, SOUTH SULAWESI

This research intends on the didactic constellation of the Luwu Kingdom community to shape the character of descendants by the convention on pangadereng values. The didactic is implemented into the cultural cohesion of dance. This research uses qualitative analysis with an ethnopedagogical or ethno-didactic approach. The continuum of this research looks at the factors in obtaining evidence, namely observation, in-depth interviews, field and non-field notes (literature review), and documentation. The didactic convergence of the Pajaga Bone Balla dance becomes a distinctive form to create a human entity with superior character, not only for particles but as a whole in every living thing. Dancers who can practice the didactic value of the dance are human beings with a degree of self-control over all lustful dependencies. The Pajaga Bone Balla dance which is intended for the sons and daughters of the Luwu dynasty is a means of life meditation to forge character to become a complete human being. Recursive research is needed to find deeper and more coherent conclusions about the constellation of intangible cultural heritage. Dissemination of revolutionary data is needed to minimize the invalidity of an object of research. The deterministic intangible culture, in this case, the Pajaga Bone Balla dance, both whose didactic dance cohesion for male dancers (Pajaga Bone Balla Tulolo) and female dancers (Pajaga Bone Balla Anak Dara), requires transparency from the aristocrat layer at the level of Luwu sovereignty so that this cultural heritage is maintained.

Preliminary study of bone biomarkers in elite female ballet dancers

Elite female ballet dancers are at high-risk of bone stress injuries (BSI) due to high-levels of weight-bearing exercise causing micro-cracks to form in the bone. The consistently high volumes of weight-bearing exercise may lead to a low BMI which reduces oestrogen levels by suppressing the gonadotrophin axis. The combination of high-levels of weight-bearing exercise and low oestrogen may be associated with increased bone remodelling. Investigating the relationship between exercise, BMI, oestrogen, and bone remodelling is crucial for developing prevention and management strategies for BSI. We conducted a pilot study of 4 weeks in a group of elite female professional ballet dancers and in female controls: the study subjects were monitored for self-reported weekly exercise, BMI, urinary oestrogen metabolites (2OHE1 and 16OHE1) and urinary NTX, a marker of bone resorption and proxy for remodelling. Measurements were collected at baseline, week 2 and 4. Dancers exhibited significantly higher hours of exercise per week (p = 0.004), and a BMI significantly lower (p = 0.030) than that of age-matched controls. In contrast, the levels of oestrogen metabolites (p = 0.050) and NTX (p = 0.460) were comparable in the two groups. Using NTX as a biomarker of bone remodelling, these results suggest that despite intense weight-bearing exercise, ballet dancers may not undergo higher bone remodelling than controls. The resulting insufficiency of bone remodelling may increase the risk of BSI because micro-cracks might accumulate in the bone faster than damaged tissue could be replaced. Based on these findings, larger studies will be designed to assess the effect of bone remodelling on BSI risk and recovery in professional ballet dancers, to develop a platform of prevention and treatment strategies including screening programmes to identify dancers at risk.

Gending Aesthetics in Janger Menyali Dance in Sawan District, Buleleng Regency

Janger dance is a variety of Balinese art which is classified as a type of social dance for young people in the form of groups (between 16-20 people), very popular among Balinese people. During the dance, groups of female dancers (janger) and groups of male dancers (kecak) dance and sing in unison (mutual sinawurin) with humorous and sometimes romantic songs. The gamelan that is usually used to accompany the Janger dance is called Batel (Tetamburan) which is equipped with a pair of gender puppets. The dance moves are still based on the aesthetic principles of Balinese dance, and the clothing uses the typical janger. Janger dance can adapt to contemporary developments, so janger activists have the freedom to interpret its form, melodies with song lyrics, musical accompaniment, and choreography. In the Janger Menyali dance, the uniqueness of this dance is in terms of the clothes that look quirky, resembling the clothes of the Dutch soldiers when they docked at the Buleleng customs, and the name for the dancers, namely for male dancers it is called jipak, while for female dancers it is called parik. In this study, it is more specific to the aesthetics of gending in the Janger Menyali dance regarding the two pieces that must be performed, namely Dewa Ayu Janger and Mepamit Ring Ratu Gusti Ayu which have the meaning of inviting Dewa Ayu Janger to attend the performance and returning Dewa Ayu Janger to return to his stana with the use of sekar alit banten properties and also kuwud mepayas.

How partnering changes the process of postural control?

The aim of the study was to identify changes in the mechanism of postural control among ballroom dancers between standing solo and standing with a partner during specific standard dance positions. Specifically, the study attempted to determine whether the male partner plays a stabilising role in the dance couple. A total of seven competitive dance couples participated in the study. The experimental procedure comprised four dance positions characteristic of international standard dances: standard, starting, chasse and contra check. The dance positions were staged twice – while standing solo and while standing with a partner. The assumption of the assessed position was preceded by a dance phase after which the participants were instructed to freeze on a force plate and hold the position for 30 s. To examine whether subjects standing solo or with partners had greater rambling (RM) or trembling (TR) components in their dance postural profile, the ratios of RM to the center of foot pressure (COP) and TR to COP were computed for velocity. No significant differences were observed in the velocity of COP between standing solo and standing with a partner (p > 0.05). However, during the standard and starting positions, female and male dancers standing solo were characterised by higher values of the velocity of RM/COP ratio and lower values of the velocity of TR/COP ratio than those standing with a partner (p < 0.05). According to the theory behind the RM and TR decomposition, an increase in TR components could indicate a higher reliance on spinal reflexes, which would suggest greater automaticity.

THE UNIQUENESS OF TELEK DANCE IN JUMPAI VILLAGE

Telek dance in Village A is a guardian or sacred dance. The dance is still maintained from generation to generation, preserved and maintained. this dance is a heritage dance that must be performed by the residents of the village because local residents believe that the dance is a form of repellent to reinforcements in order to be given safety and keep village A away from the plague, the dance is performed once every 15 days which coincides with rahinan kajeng kliwon. The Telek dance in Jumpai village is estimated to have developed around 1935 until now. the Telek dance in there was performed by 4 male and female dancers who were still classified as children (approximately 6-12 years old). The purpose of this research is to show the value of function and meaning in Telek dance in village A. The values in Telek dance include; religious values, cultural values, knowledge values, and skills values. This dance is danced with a duration of 14 minutes.

Oleg Tamulilingan with Badung Style as the Primadona in the Performance Arts of Bali Tourism

The Oleg Tamulilingan dance is a traditional Balinese dance with the theme of romance, which depicts the romance of male and female beetles, danced in pairs by a male and female dancer. Researchers have extensively discussed the popularity of the Oleg Tamulilingan Dance. But, no one has disclosed the Badung Style in Oleg Tamulilingan Dance has remained the primadonna of the Bali tourism industry. The question is: what is the structure of the Badung version of the Oleg Tamulilingan dance?; What is the origin of the Badung-style Oleg Tamulilingan dance?. This research was conducted using qualitative methods. The data sources for this study were: Oleg Tamulilingan with Badung Style Dance, dancers, musicians, dance teachers, artists, humanists, experts, and related communities who were selected based on purposive sampling and snowball techniques. All data that has been collected through observation, interviews, and literature studies was analyzed qualitatively. The results of the research show that the Badung Style in Oleg Tamulilingan Dance is performed in the form of a loose dance depicting a male and female beetle making out in a flower garden. This can be seen from the way it is presented, the makeup and clothing, as well as the musical accompaniment used. The structures used in the Oleg Tamulilingan with Badung Style performance are pepeson, pengawak, and pengecet. The emergence of the Badung Style in Oleg Tamulilingan dance was caused by internal and external factors. The internal factor of the Oleg Tamulilingan Dance is the talent of the first dancer, Gusti Ketut Raka Astuti, who teaches his students. The external factor is the development of tourism, which provides an opportunity for the development of the Badung Style in Oleg Tamulilingan Dance and has implications for the enrichment of the presentation model of the Oleg Tamulilingan Dance.

Self-reported perceived stress, depression, and generalized anxiety disorder among Kathak dancers and physically active non-dancers of North India.

The aim of the present paper was to study the various common mental disorders in a sample of Kathak dancers and non-dancers of North India. 206 female Kathak dancers and 235 healthy controls, aged 18-45 years completed questionnaires assessing perceived stress (PSS-10), depressive symptoms (PHQ-9), and generalized anxiety (GAD-7). Pearson correlations assessed the association between perceived stress, depression, generalized anxiety, age, and years of dancing, and binary logistic regression identified the risk of developing depression and generalized anxiety disorder in Kathak dancers and non-dancers. The prevalence of perceived stress was similar among Kathak dancers and non-dancers. Kathak dancers reported significantly lower depressive symptoms compared to controls. Non-dancers with elevated perceived stress levels were 4 times more likely to report depressive symptoms and 7 times more likely to report anxiety symptoms, relative to dancers. The adjusted odds of reporting depressive symptoms along with generalized anxiety were higher among non-dancers compared to dancers. Kathak can be developed into a very effective psychotherapeutic tool for mitigating the risk of developing depression and generalized anxiety disorder.

Dancers with non-specific low back pain have less lumbar movement smoothness than healthy dancers

BackgroundBallet is a highly technical and physically demanding dance form involving extensive end-range lumbar movements and emphasizing movement smoothness and gracefulness. A high prevalence of non-specific low back pain (LBP) is found in ballet dancers, which may lead to poor controlled movement and possible pain occurrence and reoccurrence. The power spectral entropy of time-series acceleration is a useful indicator of random uncertainty information, and a lower value indicates a greater smoothness or regularity. The current study thus applied a power spectral entropy method to analyze the movement smoothness in lumbar flexion and extension in healthy dancers and dancers with LBP, respectively.MethodA total of 40 female ballet dancers (23 in the LBP group and 17 in the control group) were recruited in the study. Repetitive end-range lumbar flexion and extension tasks were performed and the kinematic data were collected using a motion capture system. The power spectral entropy of the time-series acceleration of the lumbar movements was calculated in the anterior–posterior (AP), medial–lateral (ML), vertical (VT), and three-directional (3D) vectors. The entropy data were then used to conduct receiver operating characteristic curve analyses to evaluate the overall distinguishing performance and thus cutoff value, sensitivity, specificity, and area under the curve (AUC) were calculated.ResultsThe power spectral entropy was significantly higher in the LBP group than the control group in the 3D vector in both lumbar flexion and lumber extension (flexion: p = 0.005; extension: p < 0.001). In lumbar extension, the AUC in the 3D vector was 0.807. In other words, the entropy provides an 80.7% probability of distinguishing between the two groups (i.e., LBP and control) correctly. The optimal cutoff entropy value was 0.5806 and yielded a sensitivity of 75% and specificity of 73.3%. In lumbar flexion, the AUC in the 3D vector was 0.777, and hence the entropy provided a probability of 77.7% of distinguishing between the two groups correctly. The optimal cutoff value was 0.5649 and yielded a sensitivity of 90% and a specificity of 73.3%.ConclusionsThe LBP group showed significantly lower lumbar movement smoothness than the control group. The lumbar movement smoothness in the 3D vector had a high AUC and thus provided a high differentiating capacity between the two groups. It may therefore be potentially applied in clinical contexts to screen dancers with a high risk of LBP.

Upper body posture in Latin American dancers: a quantitative cross-sectional study comparing different postures

BackgroundIn Latin American dance sport (LD), the shoulder girdle and the torso area are particularly stressed due to the dance style specific requirements. The aim of the study was to define differences in various dance specific upper body postures in Latin American dancers and to show gender-specific differences.MethodsThree dimensional back scans were performed in n = 49 dancers (28 f/21 m). Five typical trunk positions in Latin American dance (habitual standing and 4 dance specific positions, P1–P5) were compared with each other. Statistical differences were calculated using the Man-Whitney U test, Friedmann test, Conover-Iman test and a Bonferroni-Holm correction.ResultsSignificant gender differences were found in P2, P3 and P4 (p ≤ 0.01–0.001). In P5, the frontal trunk decline, the axis deviation, the standard deviation of the rotation, the kyphosis angle and the shoulder as well as the pelvic rotation were also significantly different. The comparison of the postures showed significant differences between postures 1–5 (p ≤ 0.01–0.001) in the males, (scapular height, right and left scapular angles and pelvic torsion). Similar results were observed for the female dancers, with only the parameters of frontal trunk decline with the lordosis angle as well as the right and left scapular angles being non-significant.ConclusionsThis study is an approach to better understand the involved muscular structures in LD. Performing LD changes the static parameters of the upper body statics. Further projects are needed to analyse the field of dance even more thoroughly.