Joint Hypermobility as a Predictor of Mechanical Loading in Dancers

Lumbopelvic Muscle Mobility and Resistance and their Association with Musculoskeletal Pain in Ballet Dancers

Objective  The present study analyzes ankle mobility and lumbopelvic muscle mobility and resistance. In addition, it identifies factors associated with musculoskeletal pain in young ballet dancers. Methods  This is a quantitative, descriptive, cross-sectional study evaluating 14 ballet dancers aged 12 to 16 years old. We used the following instruments: a) Nordic Musculoskeletal Symptom Questionnaire (NSQ) for musculoskeletal pain assessment; b) leg lateral reach test, lumbar lock, and rotation test (for trunk mobility analysis) and lunge test (for ankle mobility evaluation); c) front bridge, lumbar extensor, and lumbar flexor muscles tests to assess lumbopelvic complex resistance. Results  The main complaints reported by ballet dancers were pain in the low back area and in the lower extremities, especially in the knee (57.1%). Those with low back pain had significantly lower lumbar mobility ( p  = 0.05) and lower ankle mobility on both sides ( p ≤ 0.05). Dancers with knee pain presented significantly lower muscular trunk extensor muscle resistance ( p  = 0.05). Conclusions  Our study revealed significant associations between the lumbopelvic complex function and musculoskeletal symptoms, supporting the implementation of preventive strategies.

External Load of Flamenco Zap-3 Footwork Test: Use of PlayerLoad Concept with Triaxial Accelerometry

The intense footwork required in flamenco dance may result in pain and injury. This study aimed to quantify the external load of the flamenco Zapateado-3 (Zap-3) footwork via triaxial accelerometry in the form of PlayerLoad (PL), comparing the difference in external loads at the fifth lumbar vertebra (L5), the seventh cervical vertebra (C7) and the dominant ankle (DA), and to explore whether the speed, position, axis and proficiency level of the flamenco dancer affected the external load. Twelve flamenco dancers, divided into professional and amateur groups, completed a 15-s Zap-3 footwork routine at different speeds. Triaxial accelerometry sensors were positioned at the DA, L5 and C7 and were utilized to calculate the total PlayerLoad (PLTOTAL), uniaxial PlayerLoad (PLUNI) and uniaxial contributions (PL%). For both PLTOTAL and PLUNI, this study identified significant effects of speed and position (p < 0.001), as well as the interaction between speed and position (p ≤ 0.001), and at the DA, values were significantly higher (p < 0.001) than those at C7 and L5. Significant single axis and group effects (p < 0.001) and effects of the interactions between the position and a single axis and the group and speed (p ≤ 0.001) were also identified for PLUNI. Medial-lateral PL% represented a larger contribution compared with anterior-posterior PL% and vertical PL% (p < 0.001). A significant interaction effect of position and PL% (p < 0.001) also existed. In conclusion, the Zap-3 footwork produced a significant external load at different positions, and it was affected by speed, axis and the proficiency level of the flamenco dancer. Although the ankle bears the most external load when dancing the flamenco, some external load caused by significant vibrations is also borne by the lumbar and cervical vertebrae.