Within- and between-day loading response to ballet choreography

Bringing biomechanics to ballet: a feasibility study using wearable technology during grand allegro

Quantifying impact accelerations during ballet class may assist load management. The largest impact accelerations occur during the sequence of large (single or double-leg) jumps (grand allegro) but are potentially the most challenging class component for utilising wearable technology, and feasibility is unknown. This pilot study utilised wearable technology during class to (1) explore feasibility and acceptability, (2) quantify impact accelerations during the entire sequence of jumps during grand allegro and (3) compare impact accelerations between limbs (preferred and non-preferred landing limb). Twelve pre-professional ballet dancers (18 ± 0.71 years old, eight females) wore inertial measurement units on each leg during class and reported acceptability. Total impact accelerations and percentage differences between limb loading during allegro were calculated. Most dancers (n = 11) reported wearable technology was feasible/acceptable during class. There were no significant differences between impact accelerations of preferred and non-preferred limb (p = 0.72) nor between limb comparison (p = 0.18). Most dancers were symmetrical (90% to 110%) in limb loading (N = 8). Wearable technology was considered acceptable during ballet class, opening future exploration of the whole class, different classes and rehearsals, as well as potential use for returning dancers back from injury.

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.