Publications

This study aimed to investigate posterior chain muscle function and the influence of pointe shoes in ballet dancers with and without low back pain (LBP) in the Arabesque.

Twenty-nine young professional ballet dancers (17 with LBP and 12 healthy controls) were recruited. Muscle strength and mechanical properties of the erector spinae and hamstrings were assessed. The displacement of centre of mass (COM) during Arabesque under different shoe conditions (R-class, Chacott, and own shoes) was measured with a motion capture system.

The LBP group exhibited greater dynamic stiffness and decreased mechanical stress relaxation time in the lateral hamstring compared to the control group. During Arabesque, the LBP group demonstrated significantly greater anterior-posterior displacement of the COM and a larger percentage of time to achieve maximal trunk extension angle. The COM displacement in vertical and medial-lateral directions was smaller in the R-class than in their own shoes.

LBP impacts muscle mechanical properties, particularly in the lateral hamstring. The compromised muscle function resulted in a longer time to spinal extension during Arabesque, signifying that reduced trunk control contributed to greater COM displacement. Hence, it is essential to emphasise that evaluating muscle properties and dynamic postural control is imperative for dancers experiencing LBP.

Keywords: center of mass, dance, muscle stiffness, lumbar segment

Ballet dancers experiencing LBP exhibit less favourable muscle mechanical properties in their lateral hamstring (i.e., increased dynamic stiffness and decreased mechanical stress relaxation time) than dancers without LBP. These altered muscle mechanical properties may contribute to the development of LBP. Furthermore, the results showed that dancers with LBP exhibited prolonged spinal extension during the Arabesque movement. This implies decreased trunk control, leading to increased COM displacement and requiring more time to achieve a specific leg height. Based on subjective ratings on three ballet pointe shoes, dancers’ pointe shoes offered more comfort, stability, and support than Chacott shoes due to their design in the performing of Arabesque. R-class shoes showed better stability but were less comfortable. Therefore, the findings from the present study suggest that dancers with LBP could focus more on the ballet movement that involves hip extension or external rotation and challenge the lower back and the mechanical properties of the lateral hamstring muscle. Furthermore, it is essential to strike a balance in the selection of footwear due to potential discrepancies between objective postural stability performance and subjective evaluations when comparing various types of pointe shoes.