Can we accurately measure multi-segment foot kinematics in ballet pointe shoes using marker-based methods?

Area of Science:

• Biomechanics
• Sports Science
• Dance Science

Background:

• Pointe shoes enable ballet dancers to rise onto their toes, but the associated biomechanical demands can increase injury risk.
• Accurate measurement of foot and ankle kinematics is crucial for understanding these demands.
• Traditional skin-mounted markers are impractical for pointe shoes due to cost and customization.

Purpose of the Study:

• To evaluate the measurement error between skin-mounted and shoe-mounted markers for capturing foot and ankle kinematics using a multisegment foot model (MSFM) during en pointe movements.
• To determine the accuracy of using external shoe markers as a feasible alternative to skin markers.

Main Methods:

• Twelve female ballet dancers performed eight distinct ballet movements.
• A validated multisegment foot model (MSFM) was employed.
• Three-dimensional (3D) kinematics were captured using an eight-camera Vicon system (250 Hz) under two marker conditions: skin-mounted (via shoe holes) and shoe-mounted (external surface).

Main Results:

• The study compared root mean square differences (RMSD) for various foot and ankle movements.
• Largest RMSD values were observed in tarsometatarsal flexion/extension (4.70°±3.47°) and subtalar inversion/eversion (4.44°±2.46°).
• Smallest RMSD values were found in ankle inversion/eversion (1.75°±1.27°) and ankle internal/external rotation (1.23°±0.87°).

Conclusions:

• A validated multisegment foot model (MSFM) with markers placed on the external surface of pointe shoes offers a relatively accurate method for capturing foot and ankle kinematics during pointe work.
• This shoe-mounted marker approach is a practical and valid alternative for biomechanical analysis in ballet dancers.
• Findings support the use of external shoe markers to advance research on pointe work safety and technique.