Morphological study of the pelvis and vertebral column in university dance major students / Estudio morfológico de la pelvis y la columna vertebral en estudiantes universitarios de danza

SUMMARY: The purpose of this study was to investigate the pelvis and spine of university dance major students. The spine and pelvic morphology were measured in 32 students (eight ballet, eight Korean dance, and eight modern dance) and eight general studies students. using dual energy X-ray absorptiometry and Formetric III 4D. First, as a result of measuring the front and rear tilt, a back tilt of the torso was found in all groups. Second, measurement of the left and right tilt of the spine showed a tilt to the right, and the angle and distance of the tilt were 1.25 ? 1.16 ? and 10.5 ? 9.3 mm, respectively in the ballet major group. Third, the kyphosis angle was the highest in the Korean dance students, exceeding the normal range (ballet: 46 ?, Korean dance: 54 ?, modern dance: 47 ?, general department: 49?). Although, there was no significant difference among the groups, but the spine and pelvic morphology were measured in different forms (shapes) according to the majors. Therefore, according to the major, the movements used to affect the shape of the spine and the pelvis are considered to change. This suggests that follow-up studies are needed. If the displacement is severe due to the movement, pain may occur and it is necessary to study how to identify the pain area when the pain occurs.

RESUMEN: El propósito de este estudio fue investigar la pelvis y la columna vertebral de estudiantes universitarios de danza. Se realizaron mediciones morfológicas de la columna y la pelvis en 32 estudiantes (ocho de ballet, ocho de danza coreana y ocho de danza moderna) y ocho estudiantes de estudios generales. utilizando absorciometría de rayos X de energía dual y formétrico ? 4D. Primero, como resultado de medir la inclinación delantera y trasera, se encontró una inclinación del torso hacia atrás en todos los grupos. En segundo lugar, la medición de la inclinación izquierda y derecha de la columna mostró una inclinación hacia la derecha, y el ángulo y la distancia de la inclinación fueron 1,25 ? 1,16 ? y 10,5 ? 9,3 mm, respectivamente, en el grupo principal de ballet. En tercer lugar, el ángulo de cifosis fue el más alto en los estudiantes de danza coreana, excediendo el rango normal (ballet: 46 ?, danza coreana: 54 ?, danza moderna: 47 ?, departamento general: 49 ?). Aunque no hubo diferencia significativa entre los grupos, la morfología de la columna y la pelvis se midió en diferentes formas (formas) según las carreras. Por lo tanto, según la especialidad, se considera que cambian los movimientos utilizados afectando la forma de la columna y la pelvis. Esto sugiere que se requieren estudios de seguimiento. Si el desplazamiento es severo debido al movimiento, este puede generar dolor y es necesario estudiar cómo identificar el área de dolor cuando ocurre.

Performance of Posture Control for Professional Dancers / 中国康复理论与实践

Objective:To explore the posture control of professional dancers. Methods:From April to August, 2017, 21 professional dancers from an international famous club were as experimental group. Matching the height and age, etc., 21 medical workers were recruited as control group. They were tested with Tetrax Balance Evaluation System, and assessed with Trunk Stability Test (TST) and the Star Excursion Balance Test (SEBT). Results:There was no significant difference on fail-time of TST and maximum distance of SEBT between right and left sides in both groups. The fail-time of TST was less in the experimental group than in the control group (t =-2.667, P < 0.05), as well as the maximum distance of SEBT (t = -3.991, P < 0.001). There was no significant difference on falling index between both groups (t = 1.810, P > 0.05). Conclusion:Compared with medical workers, professional dancers do better in static balance, but worse in dynamic balance. Their performance of posture control is almost the same as the others.

Análise cineantropométrica da volumetria e composição percentual muscular dos segmentos apendiculares de bailarinos de elite de Cuba / Kinanthropometric analysis of the volume and muscle percentage composition of the appendicular segments of Cuban elite dancer

INTRODUÇÃO E OBJETIVO: Um bailarino de balé com grande potencialidade de eficiência de movimento técnico transitivo deve mostrar porcentagens de áreas musculares dos segmentos apendiculares em uma volumetria espacial que não o qualifique como feio na sua figura. O propósito desta investigação é comparar a volumetria e composição percentual muscular dos segmentos corporais dos dançarinos de elite de balé com relação à dança moderna e folclórica. MÉTODOS: Realizou-se um estudo antropométrico dos melhores dançarinos cubanos das companhias Balé Nacional de Cuba (BCN), Dança Nacional (DN) e Conjunto Folclórico Nacional (CFN). Seguindo o critério de seleção dos professores, quanto à figura e o desempenho técnico artístico, mediram-se os melhores dançarinos de cada companhia, com idades entre 18 e 40 anos. Aplicou-se um protocolo antropométrico de 10 medições. Utilizaram-se as equações do modelo geométrico de cálculo das áreas transversais totais e musculares dos segmentos apendiculares para estimar a volumetria e composição muscular. RESULTADOS E CONCLUSÃO: A expressão quantitativa das áreas totais por segmentos - em suas múltiplas relações de similitude e diferença - ratificaram os enunciados empíricos que referem um critério diferencial de beleza cênica corporal para os bailarinos de ambos sexos do BNC, em relação aos de DN e CFN. Os dados demonstraram que a linearidade morfológica de um bailarino de elite é independente da expressão de uma potencialidade menor - exceto para a dançarina do CFN - de eficiência do movimento técnico transitivo.

INTRODUCTION AND OBJECTIVE: A ballet dancer with great potential of efficiency for technical transitive movement should show muscle area percentages of body segments in some range of spatial volume that does not classify him /her as an ugly figure. The purpose of this article is to compare the volumetry and percentages on the muscle composition of body segments for elite ballet dancers, with modern-folkloric dancers. METHODS: The best dancers of the Cuban National Ballet (BNC), National Dance (DN) and National Folkloric Group (CFN). The best dancers -ages between 18 and 40 years - were measured following the selection criteria of expert teachers about body shape and technical-artistic performance. An anthropometric protocol of 10 measurements was applied. The equations of geometric model to estimate the total and muscle cross sectional areas of body segments were used, in order to determine the volume and muscle composition. RESULTS AND CONCLUSIONS: The quantitative expression of total cross sectional areas for body segments -in their many relations of similarity and difference- confirmed the empirical statements about a specific criterion of body scenic beauty for both sex dancers from BNC comparing with DN and CFN. Data demonstrated that morphological linearity of an elite dancer is independent from a less potential-except for female dancer from CFN- of efficiency for technical transitive movement.

COMPARISON OF TRUNK ACCELERATIONS AND KNEE FLEXION ANGLE DURING THREE TYPES OF LANDING BETWEEN BALLET DANCERS AND NON-DANCERS / 体力科学

<b>Purpose:</b> The purpose of this study was to determine whether the impact on the body during landing in dancers is less than in non-dancers by using accelerometers and motion analyzer.<b>Method:</b> Eleven ballet dancers and 11 non-dancers participated in this study. Each subject was instructed to perform 3 types of landing from a height of 30cm: <i>landing, silent landing</i> and <i>raise up landing.</i> Markers were put on the iliac crest, greater trochanter, knee joint, lateral malleolus. The peak vertical and horizontal accelerations of the lumbar, peak vertical acceleration of the greater trochanter and the peak flexion angles of the hip and knee joints were measured after the trials.<b>Result:</b> In the <i>raise up landing,</i> the peak vertical acceleration of the lumbar region in dancers was less than that in non-dancers (p < 0.01), and the peak knee-flexion angle in dancers was greater than that in non-dancers (p < 0.01). There were no differences between the peak hipflexion angles of dancers and non-dancers.<b>Conclusion:</b> The impact on the lumbar during <i>raise up landing</i> was less in dancers. In <i>raise up landing,</i> the trunk tends to be fixed when the dancer stands upright. Moreover, dancers attenuated the shock to the lumbar region by increasing the knee-flexion angle to a greater extent than the non-dancers did. This result may indicate the importance of the knee joint flexion in attenuating the shock during landing and show that dancers excel in using their knees flexibly.

Bailarinos profissionais e saúde: uma revisão da literatura / Professional dancers and health: a literature review

O bailarino é um artista com demandas físicas comparáveis às de um atleta de alta performance e a um profissional de dedicação integral, com um longo período de formação. A saúde do bailarino apresenta especificidades, ainda pouco investigadas. As lesões musculoesqueléticas são o maior enfoque da literatura, em virtude das altas incidências. Muitos são os fatores de risco de lesão descritos entre bailarinos. Citam-se idade, gênero, tempo de prática, índice de massa corpórea, treino suplementar, fatores ambientais e biomecânicos. Mais recentemente, foram descritos fatores psicológicos. O tratamento das lesões muitas vezes é postergado em virtude dos compromissos profissionais e do medo do afastamento. Há evidências de que as estratégias de tratamento e prevenção podem diminuir a incidência de futuras lesões. A literatura é recente e heterogênea, o que limita conclusões mais consistentes. Nota-se que fatores relativos à dinâmica e ao processo de trabalho ou a aspectos organizacionais são raramente pesquisados. Uma nova forma de aproximação é necessária para melhor compreensão do processo saúde/doença do bailarino profissional.

The dancer is an artist with high physical demands who can be compared with an athlete of a high performance and a professional of integral devotion, with a long period of formation. Dancer’s health has specific features that are still little investigated so far. Musculoskeletal injuries are the most frequent focus of the studies, due to their high incidence. There are many risk factors described in dancers, like: individual’s characteristics as age, gender and time of practice, body mass index (BMI), supplementary training, environmental factors, biomechanical factors, and more recently, psychological factors have been more focused in the studies. Also, the treatment of injuries is usually delayed because of professional commitments, aggravated by the fear of missing show sessions. Preliminary evidences suggest that appropriate strategies of treatment and prevention could avoid the development of further injuries. The literature on this issue is young and very heterogeneous, limiting more consistent conclusions. It is also observed that factors related to work process and dynamics, as well as work organization, are poorly approached, so far. So, new approaches are required in order to improve the understanding on the health disease process in professional dancers.

Posterior Impingement Syndrome of the Ankle Joint in Classical Ballet Dancer / 대한정형외과학회잡지

In the classical ballet dancers, ankle joints are frequently overused. Especially the Pointe and the Releve are the two basic steps of ballet dance which cause the narrowing of the posterior aspect of the ankle joint. Posterior impingement syndrome of the ankle joint is defined as impingement occuring at the anatomical interval between the posterior tibial articular surface and os calcis. The purpose of this study is to describe the anatomy and etiology of this injury and to review the non-operative and operative treatments. Sixteen cases of posterior impingment syndrome had been treated between March 1994 and March 1995. Ten dancers were professional and six were students. The patients was divided 3groups by etiologic factor. Group 1 is anatomical problem factor, Group 2 is overuse factor and Group 3 is ankle sprain factor. Thirteen dancers (81.2%) improved with conservative treatment including local steroid injection. Among the other three dancers, operation was performed in one case. The other two cases stopped dancing. The result was good in one dancer after operation. In the classic ballet dancers, posrerior impingement syndrome was frequent disorder and major etiologic factors are anatomical problem and overuse. Operation was necessary in only group l. It is good result in conservative treatment and operation.

Bone Mineral Densities in Ballerinas, Korean Traditional Dancers and Athletes / 대한정형외과학회잡지

Evidence in human studies of the association of long term habitual exercise with bone mineral content (BMC) and bone mineral density (BMD) mostly come from studies done on athletes. The highest BMC and BMD values in young adults have been found in strength and power-training athletes, while endurance activities such as long distance running and swimming seem to be less effective in obtaining peak bone mineral density. To compare the differences in BMD among ballet, Korean traditional dancing and athletics, we examined the BMD of 10 ballerinas, 10 Korean traditional dancers, 12 athletes and 12 volunteers as the control group. All participants were female. The average age were 20.6 years for the ballerinas, 21.2 for the Korean traditional dancers, 20.4 for the athletes and 21.3 for the control group. Average weights were 50.6 kg for the ballerina, 53.7 kg for the Korean traditional dancer, 59.2 kg for the athletes and 53.8 kg for the control group. Average heights were 162.0 cm for the ballerinas, 160.4 cm for the Korean traditional dancers, 162.3 cm for the athletes and 160.5 cm for the control group. There were no significant differences in the BMD values of the proximal femur and the lumbar spine between ballerinas and control group and between Korean traditional dancers and control group (p>0.05). There was, however, a significant increase of BMD in the proximal femur and lumbar spine of the athletes when compared with the control group (p0.05). Differences of BMD values between the ballerinas and control group was statistically significant only in femoral neck (p<0.05).