Kinematic repeatability of a multi-segment foot model for dance^*

* The study protocol was approved by Edith Cowan University Research Ethics Committee. The authors certify that they have no affiliations with or financial involvement in any organisation or entity with a direct financial interest in the subject matter or materials discussed in the article.

This work was presented at the 26th Annual Conference of the International Association for Dance Medicine & Science held in Wanchai, Hong Kong, October 2016.

Abstract

The purpose of this study was to determine the intra and inter-assessor repeatability of a modified Rizzoli Foot Model for analysing the foot kinematics of ballet dancers. Six university-level ballet dancers performed the movements; parallel stance, turnout plié, turnout stance, turnout rise and flex-point-flex. The three-dimensional (3D) position of individual reflective markers and marker triads was used to model the movement of the dancers’ tibia, entire foot, hindfoot, midfoot, forefoot and hallux. Intra and inter-assessor reliability demonstrated excellent (ICC ≥ 0.75) repeatability for the first metatarsophalangeal joint in the sagittal plane. Intra-assessor reliability demonstrated excellent (ICC ≥ 0.75) repeatability during flex-point-flex across all inter-segmental angles except for the tibia-hindfoot and hindfoot-midfoot frontal planes. Inter-assessor repeatability ranged from poor to excellent (0.5 > ICC ≥ 0.75) for the 3D segment rotations. The most repeatable measure was the tibia-foot dorsiflexion/plantar flexion articulation whereas the least repeatable measure was the hindfoot-midfoot adduction/abduction articulation. The variation found in the inter-assessor results is likely due to inconsistencies in marker placement. This 3D dance specific multi-segment foot model provides insight into which kinematic measures can be reliably used to ascertain in vivo technical errors and/or biomechanical abnormalities in a dancer’s foot motion.

Keywords:

• Biomechanics
• en pointe
• ballet
• joint rotation

Acknowledgements

The authors would like to thank the dancers from the Advanced Diploma of Dance programme at the Western Australian Academy of Performing Arts at Edith Cowan University who participated in this study. No funding was received for this study. Sarah L. Carter would like to acknowledge the financial support the Australian Postgraduate Award (APA) scholarship. Nahoko Sato would like to acknowledge that this work was in part produced during a sabbatical research fellowship supported by Nagoya Gakuin University.

Notes

* The study protocol was approved by Edith Cowan University Research Ethics Committee. The authors certify that they have no affiliations with or financial involvement in any organisation or entity with a direct financial interest in the subject matter or materials discussed in the article.

This work was presented at the 26th Annual Conference of the International Association for Dance Medicine & Science held in Wanchai, Hong Kong, October 2016.