Balance control, hamstring flexibility and range of motion of the hip rotators in ballet dancers

Clarifying the relationships between trunk muscle endurance, respiratory muscle strength and static/dynamic postural control in Latin dancers

Sufficient study has not been performed to clarify the role of trunk/respiratory muscles strength/endurance in providing postural control in dancers. The purpose of this study was to identify predictors affecting static/dynamic postural control in Latin dancers and to compare these measurements with non-dancers. The study included 38 (26F; 12 M) Latin dancers and 33 (21F; 11 M) non-dancers. Static/dynamic postural control, trunk muscle endurance, respiratory muscle strength/pulmonary functions, flexibility, and reaction tests were assessed with a force platform system, the McGill battery, spirometer, sit-and-reach test and Nelson-reaction-tests, respectively. Trunk muscle endurance times, respiratory muscle strength, FEV1/FVC, gender, hours of training per week and dancing experience were significant predictors of static/dynamic postural control in dancers (p < 0.05). All the trunk muscle endurance times, reaction tests results, and maximal inspiratory pressure were higher in the dancers compared to the non-dancers (p < 0.05). The limits of stability for forward and backward directions were higher, and anteroposterior sway in normal stability with eyes open was lower in the dancers compared to the non-dancers (p < 0.05). Trunk muscles endurance, respiratory muscle strength, dancing experience, and hours of training per week were positively associated with static/dynamic postural control. These predictors should be taken into consideration to improve postural control in dancers.

Flexibility of Ballet Dancers in COVID-19 Pandemic: A Prospective Observational Study in Portugal

The aim of this study was to verify how dancers’ flexibility work has developed during confinement through four assessment moments: before, during (two times), and after the lockdown period. The sample was formed by 18 dancers from the Porto Dance Conservatory (Portugal) with an average age of 11.4 ± 1.4 years and 1.4 ± 0.7 years of experience. To assess the passive and active flexibility level, we used seven of the International Gymnastics Federation’s recommended tests using main joints (i.e., hips and spine). The first evaluation was performed before the pandemic situation began in a training environment, and the second and third evaluation were performed during the lockdown, in home environment, and in virtual trainings. Finally, the last evaluation was carried out in a training environment after returning to face-to-face activities and with several rules such a social distancing and mask use. The results showed that significant improvements were verified in the flexibility level of the dancers from the first to the fourth moment of evaluation. In the current study, no statistical significance was noted for the decreased values of functional asymmetry between the preferred and non-preferred lower limbs. These differences may have substantial relevance for dancers’ harmonious body development.

Kinematics and Esthetics of Grand Battement After Static and Dynamic Hamstrings Stretching in Adolescents

The objective of this study was to explore the effects of static and dynamic hamstring muscles stretching on kinematics and esthetics of grand battement (high velocity kicks) in adolescent recreational dancers. Sixteen participants were assessed before and immediately after both stretching modalities. Kinematics of movement was measured by an optoelectronic system and esthetics was scored by a jury of professional dancers. Both stretching modalities led to significant kinematic differences compared with without stretching. Significant linear correlations between kinematic parameters and esthetic scores have been observed: improving dancers' physical performances has noticeable impact on the perception of their movements.

Hamstring extensibility differences among elite adolescent and young dancers of different dance styles and non-dancers

Background

Hamstrings have been analyzed extensively due to their tendency to shorten and their effect in the lumbo-pelvic dynamics and the sagittal position of the spine in trunk flexion with extended knees positions. It has been demonstrated that practicing a certain sport results in long-term changes in hamstring extensibility. Despite this, adequate extensibility of the hamstring musculature is essential for the dancer’s performance. Several studies have found differences in the extensibility of the hamstrings depending on the dance style, but none have compared ballet, Spanish dance and modern dance. The purpose of the present research was to analyze the differences in hamstring extensibility among professional dance students based on dance style practiced and non-dancers.

Methods

The sample was comprised of 210 students from the Professional Dance Conservatory (70 for ballet, 70 for Spanish dance and 70 for modern dance) and 70 non-dancers. For the assessment of hamstring extensibility, the angle in the passive and active straight leg raise (PSLR and ASLR, respectively) test, and the scores of the pelvic tilt in sit-and-reach (SR) test and the toe-touch (TT) test were randomly conducted.

Results

The results showed significant differences for all the tests according to group (p < 0.001). In the PSLR and ASLR test, for both legs, and in the pelvic tilt in the SR test, the ballet dancers showed greater ranges of hamstring extensibility than the modern dancers and Spanish dancers (p ≤ 0.001). In the distance in the SR test and in the pelvic tilt in the TT test, the ballet dancers obtained higher values than the Spanish dancers (p = 0.004 and p = 0.003, respectively). The modern dancers showed higher ranges of hip flexion than the Spanish dancers in the ASLR test for both legs and in the pelvic tilt in the SR test (p from 0.007 to <0.001). Dancers showed significantly higher hamstring extensibility than non-dancers in all the tests (p < 0.001).

Conclusions

The systematic practice of dance, regardless of the style, seems to lead to high ranges of hamstring extensibility. Ballet dancers have the greatest hamstring extensibility.

Contralateral Muscle Imbalances and Physiological Profile of Recreational Aerial Athletes

BACKGROUND

Aerial fitness is quickly gaining popularity; however, little is known regarding the physiological demands of aerial athletes. The purpose of the study was to examine contralateral muscle imbalances, compare dominant versus non-dominant hamstrings-to-quadriceps (H:Q) ratios, and to establish a physiological profile of recreational aerial athletes.

METHODS

Thirteen aerialist women visited a local aerial studio to participate in a data collection session to examine isometric levels of upper and lower body strength, muscle endurance, flexibility, balance, and cardiovascular fitness.

RESULTS

No significant differences were found between dominant and non-dominant hand grip strength (p = 0.077), dominant and non-dominant isometric knee flexion (p = 0.483), dominant and non-dominant isometric knee extension (p = 0.152), or dominant and non-dominant isometric H:Q ratios (p = 0.102). In addition, no significant difference was found between isometric dominant H:Q ratio and the widely-used value of 0.60 (p = 0.139). However, isometric non-dominant H:Q ratio was significantly lower than the 0.60 criterion (p = 0.004). Aerial athletes demonstrated to have excellent flexibility, balance, cardiorespiratory fitness, and average strength.

CONCLUSIONS

Aerial fitness may be another recreational activity that could be used to maintain higher levels of flexibility, balance, cardiorespiratory fitness, and strength. Aerialists may want to consider focusing on strengthening the lower body and balancing the hamstrings and quadriceps muscle strength.

POSTURAL PROFILE OF CLASSICAL BALLERINAS FROM THE VALE DO SÃO FRANCISCO REGION OF BRAZIL

ABSTRACT Objective: The study aimed to determine the association between postural changes and practice of classical ballet among ballerinas from Integrated Administrative Region of Development (RIDE) in Polo Petrolina/PE and Juazeiro/BA. Methods: Cross-sectional observational study with 19 classical ballerinas aged over 15 years and at least 5 years of uninterrupted classical ballet practice. The anthropometric assessment included measurements of total body mass, height and body mass index (BMI). Postural evaluation was performed using the photogrammetric method with help of Posturograma(r) and SAPO(c) software. Results: The mean age was 25.3±11.7 years and the mean BMI was 21.4±2.9 kg/m². Approximately 74% of classical ballerinas had normal anthropometric profile. The postural profile of the classical ballerinas showed inclination and protrusion of the head, trunk rotation, rectification of cervical lordosis, increased thoracic kyphosis, increased lumbar lordosis, pelvic inclination and anteversion. Conclusion: The practice of ballet led to changes in body alignment of the classical ballerinas evaluated. The results points out to the need of postural re-education in order to contribute for the kinetic-functional balance of classical ballet practitioners.