Jumping Asymmetries and Risk of Injuries in Preprofessional Ballet.

BACKGROUND: Preprofessional ballet dancers are exposed to the risk of injuries, primarily in the lower extremities, with most injuries occurring during jumping and landing activities. Interlimb asymmetry during jumping and landing activities has been associated with the injury risk in adolescent athletes, but this has not been examined in dancers. PURPOSE: To investigate associations between interlimb asymmetry during a double-leg countermovement jump (DL-CMJ) and single-leg jump (SLJ) and the injury risk in adolescent preprofessional ballet dancers. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Adolescent preprofessional ballet dancers (N = 255) performed 3 DL-CMJs and 3 SLJs on force plates during annual screening. Absolute and directional (separate values for left and right limb dominance) asymmetries in a set of kinetic variables during a DL-CMJ and in jump height during an SLJ were calculated. Each variable was characterized as having "high" or "normal" asymmetry according to the percentage of asymmetry (greater than or less than or equal to, respectively, the mean ± 0.5 SD) based on the present sample. Risk ratios (RRs) and 95% CIs were calculated based on the injury incidence in the subsequent academic year. RESULTS: Of the 242 dancers that satisfied the inclusion criteria, 128 injuries were observed in the subsequent academic year. In the whole sample, 3 absolute, 7 left limb-dominant, and 1 right limb-dominant kinetic asymmetry in the eccentric, concentric, and landing phases of the DL-CMJ as well as left limb-dominant jump height asymmetry in the SLJ were associated with a significant (P < .001) increase in the injury risk (RR, 1.28-1.69 [95% CI, 1.02-2.37]). Separating by sex, asymmetries in the eccentric and landing phase of the DL-CMJ were not significant in boys, while in girls, RRs for asymmetries in the eccentric and landing phase of the DL-CMJ increased, and SLJ jump height asymmetry was not significant. CONCLUSION: Higher asymmetries in certain kinetic variables during the DL-CMJ and in jump height during the SLJ were associated with an elevated risk of injuries in elite preprofessional ballet dancers with some sex-specific differences. Associations were mainly identified for high left limb-dominant asymmetry in the takeoff phase, suggesting that the injury risk may be specific to a relative right limb deficit.

The Use of Physical Screening Tools to Identify Injury Risk Within Pre-Professional Ballet Dancers: An Integrative Review / El uso de herramientas de cribado física para identificar el riesgo de lesiones en los bailarines de ballet preprofesionales: Una revisión integradora

Objective. To conduct an integrative review of all relevant research investigating the physical risk factors for injury within pre-professional ballet dancers, to provide insight that may benefit practitioners within these institutions and highlight areas for future research within this specialised population.Design. Studies were identified from the following electronic databases: MEDLINE via PubMed, SPORTDiscus via EBSCOhost, and Web of Science Core Collection via Web of Science. 8,415 titles were identified during the electronic search process. Five studies satisfied the inclusion criteria and were included in the review. The mod-ified Agency for Healthcare Research and Quality (AHRQ) scale for observational studies was used to assess study quality.Results. The review identified that the following physical characteristics may influ-ence prospective injury risk in pre-professional ballet dancers: age and maturation status, anthropometrics and body composition, strength and power, joint mobility and range of motion, specific dance function, and cardiorespiratory fitness.Limitations. The research identified lacked methodological quality. This, com-bined with the low number of studies identified, makes the design of screening pro-tocols challenging for practitioners.Originality. Despite the number of pre-professional balletic institutions worldwide, previous reviews have not used a systematic search strategy or investigated both sexes in this cohort. Due to the unique demands of ballet, an understanding of the inter-action between injury and physical characteristics is a critical step in order to reduce injury burden. Conclusions. This review succeeded in determining risk factors for injury within this population, but, due to insufficient evidence, could not provide robust screening recommendations

Objetivo. Llevar a cabo una revisión integradora de toda la investigación relevante sobre los factores de riesgo físico de las lesiones en los bailarines de ballet preprofesionales, para proporcionar una visión que pueda beneficiar a los profesionales de estas instituciones y resaltar las áreas para futuras investigaciones en esta población especializada. Diseño. Los estudios se identificaron en las siguientes bases de datos electrónicas: MEDLINE vía PubMed, SPORTDiscus vía EBSCOhost y Web of Science Core Collection vía Web of Science. Se identificaron 8.415 títulos durante el proceso de búsqueda electrónica. Cinco estudios cumplieron los criterios de inclusión y se incluyeron en la revisión. Para evaluar la calidad de los estudios, se utilizó la escala modificada de la Agency for Healthcare Research and Quality (AHRQ) para estudios observacionales. Resultados. La revisión identificó que las siguientes características físicas pueden influir en el riesgo prospectivo de lesiones en los bailarines de ballet preprofesionales: edad y estado de maduración, antropometría y composición corporal, fuerza y potencia, movilidad articular y amplitud de movimiento, función específica de la danza y aptitud cardiorrespiratoria. Limitaciones. La investigación identificada carecía de calidad metodológica. Esto, combinado con el bajo número de estudios identificados, hace que el diseño de protocolos de detección sea un reto para los profesionales. Originalidad. Las revisiones anteriores no han utilizado una estrategia de búsqueda sistemática ni han investigado ambos sexos en esta cohorte. Debido a las exigencias únicas del ballet, la comprensión de la interacción entre las lesiones y las características físicas es un paso fundamental para reducir la carga de lesiones. Conclusiones. Esta revisión logró determinar los factores de riesgo de lesiones dentro de esta población, pero, debido a la insuficiencia de evidencia, no pudo proporcionar recomendaciones sólidas de cribado.